Cummins – RoadTraveler.net

November 3, 2024November 12, 2024

Mickey Thompson Baja Boss A/T LT255/85R17

Mickey Thompson Baja Boss A/T LT255/85R17

The Baja Boss A/T was introduced to automotive journalists during the virtual 2020 SEMA Show with a press embargo date of April 5, 2021. After the embargo Mickey Thompson sent me a set for a long-term evaluation, which was published in the Turbo Diesel Register magazine. For my initial review I chose a popular 18-inch size aiming for the broadest appeal for those with newer trucks. In that piece I shared that Mickey Thompson introduced a new niche size, the LT255/85R17, that I also wanted to evaluate.

LT255/85R17E is a cool, new, niche size.

Overview

The Baja Boss A/T is a fairly high-void, four-rib tread design that Mickey Thompson calls a hybrid, AKA a commercial traction or an aggressive all-terrain. Absorbed by sister brand Mickey Thompson a few years ago, the legendary but now defunct Dick Cepek company arguably invented the first hybrid tread in 1978, when Mr. Dick Cepek introduced the first Fun Country. This was long before anyone used the word hybrid to describe tires, and before several other manufacturers started emulating these versatile and multifaceted designs.

2014 version of the Dick Cepek Fun Country.

When compared to a more conservative all-terrain or all-season, the deeper and higher-void tread offers better resistance to hydroplaning and superior grip on deeper snow and moderate mud. These attributes are often combined with rugged carcass construction, and if the right special sauce is used for the tread compound sometimes they also offer superior longevity.

Continually reducing road noise while improving other benefits of traction designs is a challenge for engineers. Historically there’s been no easy solution, because better traction in sloppy conditions requires bigger blocks and voids, which increases road noise. The Baja Boss A/T is quieter than it looks.

Mickey Thompson’s Baja Boss A/T has been a favorite since its 2021 introduction.

According To Mickey Thompson

Mickey Thompson says the Baja Boss A/T blends Extreme Sidebiters® for a bold look and serious grip with an all-new silica-reinforced compound providing long-wear, all-weather performance and cut/chip resistance.

Design highlights include:

Large surface-area tread elements for a greater contact area
Shoulder scallops for an additional biting edge
Sound-deadening ribs for stability and a quiet ride
Enhanced stone ejectors to reduce debris retention
PowerPly XD™ with 50 percent heavier denier cord on the biased-angled third ply for protection, handling and stability
Rim flange protector for added wheel protection
3 Peak Mountain Snowflake (3PMS) symbol certifies that all sizes 12.50 (315mm) and narrower are Severe Snow Service rated
50,000-mile treadwear warranty
Increased-load LT-Metric sizing for heavy-duty applications
Lower-load floatation sizing for half-ton, lighter trucks and SUVs
A 35-inch tire approved for 17×6.5 dually wheels

That last bullet point is the specific size this review is about, the LT255/85R17 Baja Boss A/T (also know as the 35×10.00R17LT). The substantial siping helps achieve the severe winter rating and increases overall grip, and measures a whopping 17/32” of the total 18.5/32” depth. Calling the sidewall rubber Extreme Sidebiters® is not an exaggeration, as they are up to 14/32” thick!

LT255/85R17 For Duallys

Dual Rear Wheel (DRW) pickups have an import role in the heavy-duty market, above the more common and very capable single rear wheel (SRW) HD trucks, but a notch below what are really medium-dutys, the 4500 and 5500 chassis. But the rear duals greatly restrict aftermarket tire options due to the spacing needed between sidewalls.

Unless someone wants to have their outside tires protruding well beyond the fenders (some do, and they think it looks cool), the DRW crowd has few choices for taller rubber that will fit otherwise stock or lightly-modified trucks. Mickey Thompson invented the new LT255/85R17 size to fill this niche. It is 35-inch-tall (34.6”), and was purposely designed to fit narrow 6.5-inch dually wheels, though it works well on wheels up to eight inches wide for SRW pickups.

When inflated to 80 psi, the 121 load-index supports 3,195 pounds each in SRW applications, or 2,910 pounds for duals. The tread has one nylon, two steel, and three polyester plies, the sidewall construction has three polyester plies, and they are made in the U.S.A.

Single Rear Wheel Use

Narrower tires will almost always clear more easily with fewer and sometimes zero modifications than a wider tire of the same height. What is also routinely overlooked because many are focused on looks, and wider is perceived as tougher and better, is that a narrower footprint usually rolls down the road more consistently, catching fewer edges, rain grooves, or semi-truck ruts. There are some people that still prefer the appearance and performance of moderate width tires (few modern LT tires are actually narrow or small), and avoid negative-offset wheels or grossly wide rubber sticking well beyond the fenders, which sling rain, snow, mud and other debris.

So it was not surprising to hear Senior Project Manager, Light Truck Division at Mickey Thompson, Ben Anderson, say that the Baja Boss A/T in LT255/85R17 has become popular with the Jeep and Toyota crowd, and others wanting taller but not needlessly wide off-road meats for their four-wheel-drives. I’m also one of those folks.

Confirming Mickey Thompson’s stated height of 34.6”. Tires are measured when mounted on a specific rim width, but not on a vehicle. Those complaining that tires are shorter than advertised when loaded by a chassis are uninformed.

Sidebar

17-inch Tires Limited to 3,195 Pounds

Why are most heavy-duty seventeens rated to support much less weight than a similar 18-inch, or even less than the same 17-inch size was in the past? Nearly all new 17-inch light-truck tires are limited to a maximum capacity of 3,195 pounds regardless of their size, psi, or theoretical capabilities.

It appears that several years ago the Tire and Rim Association (TRA) decided to lower the maximum load index for seventeens. Or maybe there was a government regulation necessitating the change? Whatever the reason, it is difficult to find high-capacity 17-inch rubber.

The official TRA load inflation charts indicate that something doesn’t compute. For example, the LT295/70R17E has 3,195 pounds of capacity when inflated to 65 psi. However, increasing the pressure to the maximum allowable 80 psi offers no increase in capacity. My basic understanding of math and science tells me that this is not how pressure and volume works inside a tire. Plus there are exceptions to the 3,195 limit.

3,970 Pound 17-Inch Anomaly

I think that if a specific tire design and/or size existed before the change, that manufacturers were grandfathered. Specific examples can be seen online, including from Toyo in their Open Country M/T line. Still using LT295/70R17E, the Toyo M/T has a load index of 128, and is rated to support 3,970 pounds at 80 psi, which makes much more sense. That is a whopping 775 pounds more than 3,195, and 1,550 pounds or 3/4-ton per axle!

For a given diameter, smaller wheels yield taller sidewalls, generally flex more, and may generate extra heat. Excessive heat is the archenemy of tires, so I theorize that this was one reason to push folks to bigger rims.

Yet there are big 16-inch sizes rated above the 17-inch, 3,195 maximum. The LT305/75R16 is rated for 3,640 pounds at only 65 psi. What gives? Are you a tire engineer reading this article? If so and you want to share some industry knowledge and history, I’d love to hear from you.

Possible Solutions

Many newer pickups come with 18-inch or larger wheels and there are many sizes that offer excellent carrying capacity. However, there are plenty of older trucks still running around on their original 17-inch rims, and they might need more capacity when hauling big loads. Proceed at your own risk, you are your own warranty station, nobody is responsible but you, etc. Depending on the specific tire, size, and manufacturer, and how one applies the science, it is possible that you may already have, or could source a 17-inch tire with more capacity than 3,195 pounds.

Mount And Balance

The Baja Boss A/T tread is asymmetric and there is a dedicated inside and outside sidewall, so they should be mounted correctly. It is possible to have a tire and wheel that is balanced according to the machine, but drives poorly. One reason can be attaching excessive weight to achieve the balance, and road force is another. As discussed in a previous article, excessive road force, or radial force variation, is a condition that can affect steering, traction, braking and load support. High road force will impart ride disturbances to the chassis and ultimately the driver.

Baja Boss A/T is an asymmetric design, with dedicated outside and inside sidewalls.

Discount Tire was hired to do the mounting and balancing.

Both the wheel weight required and the road force measurements were extremely low for this set of Mickey Thompsons. An acceptable maximum road force measurement for passenger car tires is 35 pounds, but all of these Baja Boss A/Ts were in the teens, which is phenomenal for a stout light-truck tire weighing 64 pounds. They were mounted on 28-pound OEM Fourth Generation 17-inch Power Wagon wheels, and the average weight needed to balance the resulting 93-pounds was only 3.9-ounces!

#1- 4.5 oz., road force 17-lb

#2- 3.75 oz., road force 11-lb

#3- 4.00 oz., road force 14-lb

#4- 3.25 oz, road force 16-lb

Data is nice, but like with many things these days we must ensure that the machines are accurate and confirm for ourselves that everything is truly working well.

Got road force? Hopefully not too much. These were perfect.

93 pounds for a modern wheel and aftermarket tire is in the normal range, but the size of the wheel and tire matters. I have a set of 20 inch tires and wheels that weigh 111 pounds, 20% more!

Wheel and tire #1 needed the most wheel weight, but that was still only 4.5 ounces.

Take It To The Limit, One More Time

My initial seat-of-the-pants freeway evaluation confirmed that Discount Tire’s balance machine was calibrated. These 255/85R17 Baja Boss A/T were fantastically smooth all the way up to 100 miles per hours and straight line tracking was excellent. I was running 58 psi in the fronts, and 40 psi in the rears, plenty for my 2500’s everyday unloaded wet weight.

The Toyo C/T is a similar heavy-duty commercial traction design and one of my all-time favorites, and a set was removed to mount the Mickey Thompsons. While the C/T are not loud for their capabilities, the Baja Boss A/T are noticeably quieter.

With low road force and minimal wheel weight, it wasn’t surprising that these LT255/85R17 Mickey Thompsons remained smooth at all speeds.

Baja Boss A/T were mounted on a set of used, scratched, but still true Power Wagon wheels. The same rims traveled up to the frozen Arctic Ocean at Tuktoyaktuk, Northwest Territories, Canada, in 2017.

Not Loud

The lack of noise from the Baja Boss A/T for the amount of void and traction impressed me back in 2021. There are similar, older treads that I still like and have run extensively in multiple sizes on several four-wheel-drives, and the Cooper Discover S/T MAXX is a great example. The S/T MAXX is a little louder when new, but once they are worn the volume increases substantially, sometimes becoming nearly as loud as a mud-terrain. The Baja Boss A/T starts and remains quieter than others, and the engineers really deserve credit. Are they as quiet as a five-rib A/T or highway tread? Of course not. As with all tires, to help reduce noise and keep your rubber wearing evenly, frequent and consistent rotations are necessary.

Ride Quality

What constitutes a good or poor ride characteristic depends on one’s performance perspective. Some prefer a softer and more compliant on-road ride, while others want or need firmer and ostensibly stronger options. Even within the LT tire category there can be huge differences between tread designs and carcass construction, even when the load index and other ratings are identical. The Mickey Thompson Baja Boss A/T is sturdy, which I prefer when using my pickup for hauling, towing, and rugged off-pavement use. The PowerPly XD™ with its 50% heavier denier cord and biased-angle third sidewall ply can be felt, but that’s to be expected and is appropriate for the intended applications.

I do prefer a somewhat softer ride during normal daily driving, but this is easily accomplished with the following two practices. I don’t combine super tall wheels with short and silly thin sidewalls (which also reduces carrying capacity), and I run close to the minimum pressure required for the weight on each axle. This means I know what my vehicle weighs, find the appropriate psi using an inflation chart, and am diligent about adding air when the load is substantially increased.

How Low Can You Go?

When unloaded I routinely run my rears between 35 and 40 psi for comfort, traction, and overall performance. The fairly soft riding 2014-and-newer Ram 2500s are not nearly as rough as the older and stiffer suspensions, but it’s still suboptimal to have overinflated tires. The ride quality difference between 80 and 40 psi with no load on the rear axle is dramatic. Over-inflation hurts grip and uneven wear is also possible.

Depending on the exact size, load index 121 tires will have a capacity of about 1,950 pounds each, or 3,900 pounds per axle at 35 psi, more than many think. One can always increase pressure to tune for their speed, ride, and overall preferences. Tires get hotter in warm weather and at higher speeds, and overheated tires can and do separate. Increasing psi for certain conditions might be desirable, but that doesn’t mean jumping from 35 psi to 80 when there is only 3,500 pounds on the axle.

In the front I typically run between 50 and 60 psi depending on the ratings and weight. The Cummins Turbo Diesel is heavy, but front axle loads are less variable so pressure adjustments are rarely needed.

60 psi up front and 39 psi on the rear axle is plenty for my truck based on the Tire and Rim Association load information charts. Your circumstances may be different.

Off-pavement crawling pressures, and much too low for regular driving. Note my minimum psi thresholds, 48 in front and 28 in the rear. These lower thresholds keep the TPMS light off unless there’s a leak and pressures are dangerously low, which is my preference. (Water-in-fuel light was triggered by a car wash.)

Light Load TPMS Light

The federally mandated Tire Pressure Monitoring System (TPMS) is an outgrowth of the Ford Explorer/Firestone debacle in the 1990s. It’s also symbolic of a larger problem, which is the unwillingness of the average driver to take responsibility for their machinery, including failing to check something as fundamentally important as tire pressure. Even with TPMS on my pickups, I regularly check and adjust pressures with a handheld gauge.

Having psi information available on the dash is great, but it’s unfortunate that Ram eliminated the light-load option around 2012, and require all 2500 owners to run pressures for maximum loads or accept a warning light on the dash. The 3500 Rams have a different system, the Tire Pressure Information System (TPIS), because their GVWR is over 10,000 pounds. TPIS provides information but does not force a warning light for running less than a predetermined and maximum pressure.

I permanently eliminated the TPMS irritant with a professional Autel MaxiSys MS906 tablet scan tool. One could argue that this was a $1,000 sledgehammer solution to dispatch an ant. True, but I purchased the Autel one year before the AlphaOBD diagnostic software was available, which reportedly works well for adjusting the pressure thresholds.

A professional automotive tablet is a super powerful diagnostic tool, and I have only used a small fraction of its capabilities. But the scanner has come in handy a few times by allowing me to discover the source of unusual problems or clear codes that were too much for my Edge CTS2.

Regardless of the tool being used, I absolutely love being able to adjust the minimum psi thresholds for both the front and rear axles to my liking, depending on the load index of the tires and my needs. My 2017 regular cab has a heavy Hallmark flatbed camper mounted full-time and the rear axle threshold’s are set higher, usually around 70 or 80 psi.

Autel tablet allows adjustment of the TPMS sensor thresholds and so much more.

Need Traction?

Traction, handling, and overall performance from the Baja Boss A/T has been impressive in all conditions and on every surface, which has included considerable dirt, gravel, rock, rain, and snow. For those wanting hybrid or commercial traction rubber I don’t envision many people wanting more grip over varied terrain than these Mickey Thompsons provide. My first set of Baja Boss A/T saw less snow than I would have preferred, not taking advantage of the three peak mountain snowflake (3PMS) rating because our local Sierra Nevada winter storms and my travels rarely overlapped in 2021. The story is dramatically different with the second set.

Got Snow and Rain? Lots Of It?

The day after mounting these LT255/85R17 on my 2014 crew cab, I made a 500 mile weekend round trip that included two crossings of the Sierra Nevada’s infamous Donner Pass. There were several inches of wet snow for dozens of miles that required four-wheel-drive. Followed by 100 miles of epic rainfall. The kind of rain that even with the windshield wipers bouncing at full speed I could barely see the roadway, similar to dangerous fog conditions, and using four-wheel-drive was beneficial because of water on the road. Throughout the remainder of winter and spring 2024, the Baja Boss A/T performed perfectly during every winter storm.

Similar to mud, the types of snow and the related driving conditions can vary greatly by region or microclimate, and opinions regarding what is good performance in certain conditions are highly subjective. For my uses I have found that the Mickey Thompson Baja Boss A/T are an excellent winter and wet weather performer under my Ram 2500.

These Baja Boss A/T have seen much snow and performed flawlessly.

Higher-void and deeper treads can perform well in heavy rain because the water can escape instead of being trapped under the tire.

Sidebiters®

Sidewall tread has become popular in recent years, even on tires that are really not intended to be used in harsh off-pavement conditions because it looks cool. However, the Baja Boss A/T Extreme Sidebiters® are legit, and are super thick and beefy. I certainly like how they look, but also put them to work for their intended purpose. If you never leave the pavement, the Sidebiters® aren’t going to complain if you drag them along curbs.

Estimated Longevity Baselines

Wear and longevity for a given tire can be highly variable depending on the vehicle, duty-cycle, and driver. One could argue that all three of these metrics (and others) are important, however, the person behind the wheel has a disproportionate effect, and will invariably influence results dramatically compared to the others.

If we were to take two identical pickups (model, gearing, transmission, tires, etc.), load them the same, and run them over a route with different drivers, it would not be surprising to see measurably different fuel economy. Covering longer distances and varied terrain would make the differences more obvious. More or less mpg is a direct result of how one operates the accelerator and brakes.

Tires and brakes are consumed more slowly than fuel, but over time the driver who gets fewer mpg and exercises less finesse and vehicle sympathy will likely also get fewer miles out of their rubber and brakes. The differences can be dramatic.

Same Guy Driving The Same Truck

No one’s truck, conditions, or driving style are identical, however, if the driver is not one of the variables the data can be more comparable. The treadwear information I’ve gathered from several four-wheel-drives over decades, particularly during the last 10 years driving the same 2014 Ram 2500 crew cab with a G56 6-speed manual transmission, provides relatively consistent and relevant information.

Wear Data

These LT255/85R17 Baja Boss A/T were mounted February 2024, have been rotated twice, and have logged 6,300 miles. Approximately 10% of those were off-pavement, including dozens at low trail pressures to improve ride, traction, and prevent damage. There is zero visible cutting, chipping or lug tearing of the tread, which is impressive considering the amount of off-highway use my truck sees. (Again, driving habits matter, and I keep tire slip and spinning to a minimum, particularly in the dirt.)

While I am smooth and conservative off-pavement, on the blacktop I routinely use all of the torque, horsepower, and rpm that my G56 version of the Cummins 6.7L has to offer with assertive application of the skinny pedal. Just like hard braking and turning fast can disproportionately wear the fronts, the massive twist of modern diesel engines can be hard on the rear drivers. Yet, that is not what I’ve experienced, there has been no penalty for my lead foot.

All Baja Boss A/T come with 18.5/32” of tread, and this set currently has about 15.5/32”, so they have given 2,100 miles per 1/32”. Those 2,100 miles compare well with other quality aftermarket traction designs, on the same truck, driven by me.

Deeper tread generally helps with traction and increases longevity. All Baja Boss A/T sizes have 18.5/32”.

For comparison, my previous set of Baja Boss A/T in 295/70R18 were run for 15,000 miles and delivered 2,300 miles for each thirty-second before they started living on a friend’s 1991 W250 Turbo Diesel. If 2,100 miles per 1/32” remains constant, these 255/85R17 Baja Boss will last 36,800 miles before reaching the minimum legal depth of 2/32”.

Baja Boss A/T is a quiet traction tire that looks good and performs extremely well, both on and off-road.

Still Love Them

After running two sets of Baja Boss A/T over the past few years I’m still enamored with this design from Mickey Thompson, and it might become my favorite hybrid all-terrain. They wear well, provide excellent traction and performance in all conditions, and are extremely rugged while still being quieter than competitors. Currently they are available in 74 sizes, for wheels from 15 to 24 inches. If you are in the market for a new set of tires you owe it to yourself to consider the Baja Boss A/T from Mickey Thompson.

Riding off into the sunset in my 2014 Cummins Turbo Diesel.

Tell ‘em you saw it on RoadTraveler.net!

Resource:

Mickey Thompson Tires: mickeythompsontires.com

November 2, 2024November 12, 2024

Mickey Thompson Baja Boss A/T LT295/70R18

Remote, northeast corner of Nevada, near the Idaho and Utah borders, BLM managed public land.

Mickey Thompson Baja Boss A/T LT295/70R18

During the November 2019 SEMA Show, I received insider information from a Mickey Thompson manager about a new Baja Boss A/T they had in-the-works; it was still more than one year from being announced. I’m a fan of the Benjamin Franklin quote “three may keep a secret if two of them are dead,” and I focus on being the one that is alive.

The Baja Boss All-Terrain was introduced to automotive journalists at the virtual 2020 SEMA Show, with a press embargo date of April 5, 2021. As soon as possible I requested a set for evaluation, choosing the LT295/70R18 size. One month later I had them.

Long-term Mickey Thompson’s Baja Boss A/T evaluation started April 2021.

As you can see in my photographs this is a fairly high-void, four-rib tread pattern that Mickey Thompson calls a hybrid, AKA a commercial traction design or an aggressive all-terrain. Tires like these have been my preference for decades, offering more potential grip via siping, self-cleaning abilities, and deeper tread than more conservative all-terrains or all-seasons, while offering a quieter driving experience, and better longevity than mudders.

Continually reducing perceived noise while improving the other attributes of these hybrid designs has been an ongoing challenge for engineers. Historically there’s been no free lunch, because much better sloppy conditions traction requires bigger tread blocks and voids, increasing road noise. Was Mickey Thompson able to achieve the impossible? Read my opinion about this below under the subheading Quiet?

According To Mickey Thompson

Design highlights include:

Large surface-area tread elements for a greater contact area
Shoulder scallops for an additional biting edge
Sound-deadening ribs for stability and a quiet ride
Enhanced stone ejectors to reduce debris retention
PowerPly XD™ with 50 percent heavier denier cord on the biased-angled third ply for protection, handling and stability
Rim flange protector for added wheel protection
3 Peak Mountain Snowflake (3PMS) symbol certifies that all sizes 12.50 (315) and narrower are Severe Snow Service rated
50,000-mile treadwear warranty
Increased-load LT-Metric sizing for heavy duty applications
Lower-load floatation sizing for half-ton, lighter trucks and SUVs
Several sizes approved for 12-inch and 14-inch wide wheels, including three 35X15.50 sizes
A 35-inch tire approved for 17×6.5 “dually” wheels

To all of the above I say yup, appears to be true! The substantial siping, which helps achieve the severe winter rating and increase overall grip, measures a whopping 17/32” of the total 18.5/32” tread depth. Calling the shoulder tread Extreme Sidebiters® is not public relations department hyperbole, as they are 14/32” at their deepest!

Extreme Sidebiters® “for a bold look and serious grip”. Truth!

Up to a whopping 14/32” of Extreme Sidebiter® on sidewalls.

Sizes are offered for wheels from 15-24”. A standout worth noting for the DRW folks or old-schoolers like me that prefer taller, narrower rubber that fits and clears more easily, offering less rolling resistance, potentially better fuel economy, etc., is the LT255/85R17. Also know-as a 35×10.00R17, this load-index 121 size supports 3,195-pounds at 80-psi in SRW applications, and would be great under my everyday crew cab. However, the 129 load-index and 18” wheel of the LT295/70R18 was a better choice for my flatbed Hallmark Camper outfit because the shorter sidewalls are firmer and more stable for maximum loads.

2017 Ram with Hallmark flatbed camper always works much harder than my 2014 crew cab daily driver.

Mount & Balance

Unless a specific tire and wheel combination requires a different solution, my standard practice is to use a single plane, so-called static spin balance, as this method requires less weight and is generally sufficient. Wider tires and wheels, super aggressive treads, or just a carcass with more lateral imbalance may require dynamic balancing, which involves putting weight on both the inside and outside of the wheel.

Many do not realize that it is often the wheel that requires the majority of the weight to balance an assembly, as modern tires are generally fantastically true. An easy way for an enthusiast to see this is by noting where wheel weight has been placed for their current and previous sets of tires. Typically the weight is needed in the same general area, pointing to imperfections in the wheel more than the tires.

According to Mickey Thompson the LT295/70R18 size weighs 67 pounds each, and they were 104-pounds when mounted to an OEM forged aluminum wheel. Maybe you should sit down before you read how little weight was needed to static balance these beautiful meats.

1) 3.0 ounces, right-rear

2) 3.25 ounces, right-front

3) 2.5 ounces, left-rear

4) 3.25 ounces, left-front

Instead of putting the rims with the least weight upfront as is common at most shops, I typically put those with the most weight on the front axle. This helps confirm that they’re truly balanced, and avoids potential surprises after the first rotation. In this instance all the wheels needed just a few ounces. I rarely have tires rebalanced, as Centramatic balancers constantly perform that task. These Bosses have been run up to well above any speed limit on numerous occasions, and they have remained insanely smooth after thousands of miles and a few rotations, living on both of my Ram/Cummins trucks.

Just a few ounces to balance the LT295/70R18E, which is continually maintained by the Centramatic balancers visible behind the wheel spokes.

Quiet!

Manufactures have been increasingly successful making beefier treads quieter, yet I routinely find that even aggressive hybrid treads that start out impressively tame get louder with wear, sometimes much louder, even with optimal rotations. (All bets are off if proper maintenance and rotations are not strictly observed.) This has not been the case with the new Baja Boss A/T, the barely audible hum has yet to increase. To my ear they are still one of the quietest, if not the quietest, tire in this category that I’ve experienced. Impressive!

Tough Enough? Extreme Puncture Resistance?

Rugged designs help prevent punctures and stout carcass construction helps tires run cooler and support big loads, translating into better performance under heavy diesel-powered rigs that do more than run around empty. Commercial tradesman applications, farming and ranching, off-pavement adventures, and RV users can all benefit from the Boss A/T’s stout construction. Are these treads as rugged as they claim? After over 14,000 miles of hard use, my answer is a resounding yes!

Designed to do work, diesel trucks can be hard on tires. Size can a limitation, but my trucks leave the pavement often, mostly in the high-desert of the Intermountain West.

My tire evaluations typically include a photo shoot off-road at low pressures in a nearby National Forest, where I flex and abuse the tread and sidewall on some rocks. It helps gauge ruggedness and flexibility, and makes for some cool photographs. Few other than dedicated a 4WD enthusiast will ever do this, particularly in a big diesel pickup…enter the James-ness!

Low pressure tire loading and flexing off-road.

Even rugged tire designs can be punctured, as they are essentially rubber balloons. However, I was thoroughly impressed with the flexibility and ruggedness of the Baja Boss All-Terrain’s when I subjected the tread, shoulder, and sidewalls to folding and pinching rarely seen outside of competitive rock crawling.

After the photo shoot, they were filled with appropriate street pressure, and have continued to perform flawlessly at all speeds and under all conditions. Tire pressure has been dropped many times to improve off-payment traction, ride, and overall performance, and the tires repeatedly work like they should.

Extreme Sidebiter® folding and pinching on the right-front tire at low pressure under a 2014 Ram/Cummins crew cab.

Some tires can take considerable abuse, obviously this tire did, but there’s always risk of damage or failure.

Application Considerations

My 2017 regular cab with Hallmark flatbed camper is a full time RV, so while it’s under a constant, full-load, it accumulates miles much more slowly than a daily driver. One would think that a heavily loaded RV-application Turbo Diesel (hauling and/or pulling) would result in rapid wear, yet that is not necessarily what happens. Chronicling treadlife on many sets of tires on my diesel pickups, and those of friends and acquaintances has provided valuable perspective.

Vehicles that see daily driving are typically subjected to repeated hard accelerations, which loads the drive tires, as well as hard stops and turning, which is harder on the fronts. These realities often contribute to reduced life compared to vehicles that see more steady, long-distance travel.

Occasional aggressive use of the skinny pedal is part of my driving style, although I am extremely soft on the brake pedal and travel slowly through most tight turns. I often obtain superior longevity and slower wear on my daily driver crew cab compared to my friends. Drivers matter.

Longevity

The Boss All-Terrains were initially mounted on my 2014 crew cab to log miles more quickly. As shared in previous columns, I am highly critical of the brief tire reviews in most magazines that say… the tires performed well, we really like them, blah blah; which is typically the result of nothing more than a few hundred miles of use, not thousands. Occasionally there’s an update later after more miles. Thousands of miles of saddle time and evaluation should be the baseline norm, not the exception.

The Boss A/Ts arrived at the perfect time, as I had started working away from home; the 2014 crew cab started seeing daily commuting miles, which included a run home during my lunch break for dog care. I’m often pressed for time, and there’s much firm use of the skinny pedal at the hands of the BD Throttle Sensitivity Booster (still LOVE it!). Due to these lifestyle changes the Boss A/Ts received harder use than any others treads in many years.

Under torque-monster diesel pickups I have repeatedly observed that approximately 1/32” of tread per 2,000 miles is good or average for an aftermarket set of rubber, and substantially more miles, 2,500 or so, is above average. For comparison, a few sets of OE Firestones I’ve measured have melted though 1/32” in a mere 1,500 miles, 25% less than my 2,000 mile baseline!

After the initial mounting and the first rotation on the 2014 crew cab, I had accumulated 6,500 miles on the Baja Boss A/Ts. Three measured 15.5/32”, and one was 15/32”, which was 2,080 mi. per 1/32” of tread depth. Considering the repeated, aggressive accelerations and fast driving this was above average; it would be just average with less spirited driving.

The Mickey Thompsons were pulled from the crew cab and slapped onto the 2017 Ram flatbed Hallmark camper rig, where they logged another 4,500 (s)miles before their third rotation. The rears were down to 13/32”, with the front wearing little and still showing 15/32. (This is part of why we must rotate.) As the tread becomes shallower the overall accuracy of measurements increases, and it’s not uncommon for the rate-of-wear to slow after these more accurate measurements. With another 3,500 miles under the Hallmark Camper, 14,500 miles total, all were showing 13/32”. The Baja Boss A/T treads had achieved 2,600 miles per 1/32”, which is well into the above average column for many diesel pickups.

After hours of slow 4WD, with several narrow and/or technical spots for such a big outfit, it was time to stop treating this rig like a side-by-side and make camp.

Traction Everywhere

Traction and handling has been impressive in all conditions and on all surfaces, which included much dirt, gravel, rock, some sand, rain, but unfortunately very little snow. It would’ve been nice to evaluate the severe winter rating more thoroughly. However, the western states multiyear drought has severely reduced precipitation in Northern Nevada and Northern California.

It’s difficult to chronicle the exact number of off-pavement miles these Bosses have seen, but a conservative estimated is 1,500 (10% is huge for non-commercial applications). Opinions regarding traction are mostly subjective, variable, and relative to the platform and driver. Nevertheless, for those wanting a hybrid tire I don’t envision people wanting more grip than the Baja Boss A/T can provide. Should the opportunity present itself I’d gladly run another set of the Baja Boss, as they’ve earned a spot on my short list of favorites.

Tell ‘em you saw it on RoadTraveler.net!

James Langan

Resource:

Mickey Thompson Tires: mickeythompsontires.com

draft

May 1, 2023November 10, 2024

WAGAN TECH DC TO DC BATTERY CHARGER

Wagan Tech’s 40 Amp DC to DC Charger

It takes some type of fuel or energy to power things, this includes humans as without food (and other necessities) our systems will shut down. In the case of our beloved Cummins-powered trucks, that energy comes from burning #2 diesel fuel. The primary output of the internal combustion is propulsion of the drivetrain; however, supporting systems give and take from the consumption, including the cooling and electrical charging systems.

Some readers know that the simple diesels from decades past would essentially run forever once started as long as the fuel flowed. They could be hard to cold-start, but they were also difficult to stop. This is because all diesels are ignited using compression ignition (CI), not a spark-ignition (SI) system like a traditional gasoline motor. Diesels are less complex without spark plugs, a coil, distributor cap and rotor, or wires, and while still fundamentally true there are modern complexities, chiefly the electronic fuel-injection.

Mandatory Electricity

Our newer, specialized, computer-controlled diesels need their modules to remain awake for everything to work properly (just like gas-powered trucks). Additionally, late-model vehicles are chock-full of countless electronic gizmos, from computer screens, cameras, seat and steering-wheel heaters, and the list goes on. The constant generation of electrical current from an alternator is no longer optional to keep the oil burning, but absolutely essential, even for daylight driving, because battery storage capacity is finite and amps consumed must be replaced.

High-output alternators easily handle the load of the Cummins cold-start grid heater, or the glow plugs in other automotive diesels, plus the increasingly popular factory-installed inverters that convert the DC current to 120-volt AC to power tools or other plug-in devices. But what about additional intermittent or constant 12-volt DC electrical loads?

Remote National Forest camping in Colorado. One only has what they bring with them.

RV Amps

The TDR readership has always included a large percentage of RVers, and because we love our pickups so much, that means mostly travel trailers, big fifth-wheels, or truck campers instead of motorhomes. Solar panels atop an RV to charge coach batteries have been common for several years, as are backup generators to energize power-hungry AC appliances like microwaves and air-conditioners when shore power isn’t available. The solar panels require sunshine, and internal-combustion generators require fuel, so additional free amperage sources are welcomed.

When an RV is connected to a truck via the 7-way trailer-towing outlet, typically a small amount of juice is delivered to the RV to help charge the coach batteries, often somewhere around 10-amps. The limitation is not alternator capability, but the size of the factory wiring. This small amount of amperage can help keep charged batteries topped if there are minimal loads; however running high-draw devices can lead to deficits.

Modern Electric-Only Refrigerators

Like modern trucks full of gadgetry, newer RVs can have unprecedented amperage draws as well. The easiest example comes from the overlanding culture where electric refrigerators pioneered the replacement of traditional RV refrigerators, which principally ran on propane or 120 volts AC when plugged-in. Some older RV refers were theoretically capable of running on 12 V-volts, but they were terribly inefficient and would drain batteries fast.

Instead of using the gas absorption method of cooling with propane, modern 12-volt refrigerators have a compressor, similar to the refrigerators in our homes. These can be built-in units, as in my Hallmark Camper, or a portable chest type refrigerator/freezer. These electric refrigerators are generally more efficient and effective, particularly in hot weather, and do not have to be leveled like a traditional RV refrigerator.

The benefits are being appreciated by more folks all the time, and in the off-grid and overland camping crowd electric fridge/freezers are seen as more rugged and vastly superior. Even the traditional RV market has noticed. My cousin recently purchased a new fifth-wheel trailer to live in (temporarily) after selling his house, and the refrigerator is 12-volt and 120-volt only, it doesn’t run on propane. There is at least one drawback and that is amperage consumption.

Large refrigerator and freezer for an 8.5-foot truck camper. Consumes up to 5-amps 12-volt DC when running.

Additional Electrical Loads

The large-for-a-truck-camper NovaKool refrigerator with a separate freezer door in my Hallmark Flatbed consumes up to 5-amps when running, and it runs a lot during the summer months. Five amps per hour adds up quickly, pulling a chunk of the total 200 amp-hour capacity we have from two, 100-amp Battle Born lithium batteries.

My Hallmark is well sealed, but no RV is or can be impervious to dust, they need to breath like a house. With this in mind, and because I spend much time traveling off-pavement and nearly always camp in the dirt, I run one of my roof vent fans while driving to pressurize the living space. This works impressively well to minimize dust intrusion. There is one more big electrical draw inside my camper every 24 hours.

Although I do not fit the physical stereotype (I’m tall and slim), I use a CPAP machine to help me breathe and sleep every night. This is another substantial electrical draw, a minimum of 4-amps, even with a dedicated 12-volt cord to avoiding the inefficiencies of an inverter. Multi-day road trips with lots of driving still result in a battery charging deficit because the factory RV 7-way provides minimal amperage. The 340-Watts of solar panels help, but they are insufficient to keep the camper batteries charged due to my consumption. A small 700-Watt 2-stroke generator travels in one of the under-bed toolboxes as an emergency back up. I prefer not to use it, and it produces a mere seven amps. So how can one easily generate more electricity?

Dead camper batteries should be old news after installing this DC charger from Wagan Tech.

Wagan Tech 40 Amp DC To DC Battery Charger

DC to DC battery chargers have been around a few years. They are popular in places like Australia, where the off-pavement backcountry travel market has historically been more robust and innovative. These devices are exactly what they sound like, taking DC amperage from the battery/alternator charging system under the hood and feeding it directly to auxiliary (RV) batteries through large wires. Sounds simple, and it is. But, they need to be hard-wired. Wagan Tech introduced their new DC to DC Battery Chargers in 2022, both a 25-amp model for $300, the $400 40-amp model that I installed.

New Hole Required

If the auxiliary battery to be charged is on the same chassis, like inside the same engine bay, the installation is easier. If secondary batteries are in a separate RV, the wiring needs to go from the host chassis into the recipient. If the RV is a trailer that is attached and disconnected regularly, then something like an Anderson plug provides a robust connector (and something I intend to add in the future).

With my Hallmark flatbed outfit, I directly connected new wires from the Cummins engine to the camper batteries, which required a new hole in my Hallmark. The process was not trouble free.

Parts and Supplies Matter

In an effort to avoid drilling a new hole, I attempted to use smaller but adequate 8-gauge gauge wires, running them alongside the existing Hallmark 7-way RV pigtail. The new positive and negative wires added too much girth to get the nut onto the knockout plate. This defeat came after hours spent running the wires from the engine bay, along the chassis, and then stuffing them next to the factory Hallamrk wiring pigtail and into the coach.

Ran these 8-gauge wires from the engine compartment, along the camper’s 7-way plug, through the existing wiring hole, but had to start over.

There wasn’t room for additional wires, I stuffed them through the knockout plate nut anyway, but couldn’t wiggle the nut up to male end to secure the plate. See the gouged insulation? That’s how tight.

When it was obvious that drilling a new hole was required I decided to use larger 6-gauge wire, good for up to 32-feet. The finished total length was less than 20-feet so the wire will easily handle the amperage. Due to time constraints the wire was purchased from a nearby Home Depot, the trade-off being that it is not as flexible or easy to work with as ever thinker, larger welding cable.

Home Depot didn’t have red 6-gauge so I had to take green. Shown with two 60A Maxi fuse holders.

Measure Multiple Times And Drill Once — A Nice Idea

The new hole in the driver’s side front wall needed to go below the water heater and above the propane locker, and it needed to be approximately 1-inch diameter. After measuring and making countless trips from the front wall into the camper, I was confident about the placement before drilling the pilot hole. Using my cordless right angle drill, I nailed it, but I assumed the 7/8″ hole saw I had was big enough, and I made a nice, clean hole. However, it was too small for the knockout plate bolt to slide from inside the camper, clamped on the 6-gauge wires, through the wall to the exterior to reach the knockout plate nut.

New 7/8” hole drilled into the front of my Hallmark Camper. Measuring and drilling went well up to this point.

Back to Home Depot to buy a larger hole saw, something near 1 1/4″. As many do-it-yourself folks know, it is relatively easy to new to drill a clean new hole, but difficult (almost impossible) to cleanly make a hole slightly larger. A few times I slowly and carefully tried to get the larger hole saw started, but, of course, the saw just slid on the fiberglass. When trying gently does not work, what is the typical response? Add force.

The Neanderthal in me came out, and I leaned on the drill to make the saw bite into the fiberglass where I wanted; this was a bad idea. The saw walked on the slippery fiberglass surface, but with increasing force it eventually dug into the exoskeleton wall, making the scar you see in the photo below. I didn’t swear much, but I was slightly displeased with myself!

Without the benefit of a centering pilot hole, I attempted to enlarge a perfectly drilled hole and made this mess instead.

Disgusted, angry, and frustrated, there was no going back, and I still needed to enlarge the hole. My solution was what I should have done after discovering the hole was just a bit too small; I ran a half-inch bit around the circumference of the hole until it was big enough.

Running a 1/2” bit around the circumference of the hole to make it larger should have been my first solution, not the second.

Thirty years ago this would have bothered me for weeks. I like to do clean, high-quality work. It’s covered by a plate and will never be an issue to anyone but me, and I’ve put it behind me. With the challenging part completed, it was time to finish the installation and get the Wagan Tech DC to DC Charger working.

Pulling And Connecting

The rest of the installation was straightforward and easy, and there were no more hiccups. I fed the 6-gauge wire through two rubber firewall boots to provide a weather barrier, one from the camper front and one from the inside, then along the frame and into the engine compartment to the driver’s side battery.

Had two of these stepped, rubber firewall boots leftover from a prior product (purchased after a prior drilling mistake). Stuffed the new hole with one from inside, and another from the front behind the knockout plate. Should be very weather resistant.

This knockout plate was always on the parts list, but also conceals my drilling snafu. Looks tidy and works too.

This Wagan 40-amp unit requires two 60-amp fuses, one as close to the engine bay battery as practical, and another on the Wagan charger output line near the auxiliary batteries. Bolt-down fuses are recommended because they have lower resistance than blade type, which can have higher resistance and create excessive heat. However, the blade-type Maxi fuses are what I found locally, and I’m confident they’ll be sufficient.

Blade-style 60A fuse holders are what was available locally.

With the incoming hot and ground wires from the engine connected to the Wagan charger, another small hole was drilled in the Hallmark’s battery box to run a hot lead from the charger to my two 100-amp lithium RV batteries.

New small hole drilled into the camper’s battery box, with the hot, output line from the Wagan 40A DC to DC Charger to a positive terminal.

With the fuses inserted I had the appropriate blinking lights on the front of the Wagan DC to DC Battery Charger; one light showing it was connected to the alternator, and after changing the battery type to LifePO4, that light was on as well. The unit is capable of working with standard, gel, AGM, and lithium batteries.

Wagan Tech’s instructions are short, simple, and easy to follow, and folks capable of doing basic wiring will likely have no problems doing this themselves. Because of the largish 6-gauge wire and connectors I used a hydraulic crimping tool, and I covered the ends with heat shrink, routed the wires as cleanly as possible, and protected them with split-loom.

60A fuse lead connected directly to the driver’s side positive post with copper ring. Heat shrink looks good and adds protection.

Mounting Options

The Wagan charger is designed for a variety of installation environments, including chassis rail, engine bay, interior cabin, etc. The unit has been designed to work in vibrating, wet, dusty and muddy environments, and can withstand temperatures of up to 176°F, so it can be installed in the engine bay. However, to get better charging efficiency, mounting the charger away from high-temperature parts is preferred.

I simply stuck it to the bottom galley shelf with mounting tape, between the propane locker and battery box. I may add screws later if this is the charger’s permanent home, but it’s not going anywhere on this flat surface.

Flashing green lights indicate the Wagan Tech DC Charger is connected to the alternator and is feeding LiFePO4 batteries. Simply stuck to a shelf inside a galley cabinet with mounting tape.

Wagan Tech DC Charger Works

Using more amperage than is being generated during long road trips should be a thing of the past. We’re unlikely to need a generator unless we want to run our air conditioner, in which case we would tote our larger Honda 2000.

Pumping a massive 40 amps per hour into the Hallmark’s lithium batteries means it takes little driving to fill them; every time we make camp the batteries will probably be full. Even if the lithiums were completely drained we could replenish all 200 amps in five hours!

Our initial adventures with Wagan DC to DC 40-amp Charger installed were extremely encouraging, the camper batteries were full whenever we stopped, and the voltage was high, as if we’d been connected to shore-power.

The Cummins is a large and expensive generator, but because we are already traveling, delivering essentially free electricity from our alternator to the camper batteries is a game-changer. Why did we wait so long to add something like Wagan’s 40A DC to DC Battery Charger?

Drive diesel and tell ‘em you saw it in the TDR! (A version of this article was previously published in the Turbo Diesel Register magazine.)

Tell ’em you saw it on RoadTraveler.net

www.RoadTraveler.net

Instagram: @RoadTraveler

YouTube: RoadTravelerNet

Resource:

Wagan Tech: wagan.com

May 7, 2018January 11, 2020

23 mpg Ram Cummins 2500

23.21 MPG from a 2017 Ram/Cummins. 65-mph highway baseline test, Sept. 5, 2017

222.7 miles, 9.593 gallons

65-mph freeway/highway test

light/no wind

A/C on

Tires: F 60 R 40 cold

Regular cab, long bed, 7,400-lb. GVW

Newer diesel trucks are not as efficient (due to emissions systems) as previous generations? Maybe. Probably. Though it depends on the exact year, model, and version. The true potential is better than some think, and the conditions, load, and nearly everything else matters.

Tests must be repeatable and confirmable. The ECM was slightly pessimistic here, and the odometer a little fast with the stock tires.

Copyright James Langan/RoadTraveler.net

February 13, 2018February 12, 2018

Cummins R2.8-Powered Proffitt’s Cruisers 79 Series Land Cruiser Pickup

Custom 79 Series Land Cruiser Pickup

Cummins’ booth at the 2017 SEMA Show was focused on their mighty mite in a crate, the fantastic R2.8 Turbo Diesel. This post is about one of the two cool rigs on display.

This Toyota was IMMACULATE! Looked NEW. Details below.

Custom 79 Series (HZJ79 body) Land Cruiser Pickup, by Proffitt’s Resurrection Land Cruisers.

-Chassis: 1993 FZJ80 (80 Series)

-Engine: Cummins R2.8

-Transmission: H55F 5-speed manual

-Suspension: 3-link front, 5-link rear

-Locking differentials

-Bilstein shocks

-Rigid lighting

-ARB front bumper

-Warn winch

-Vortex Sprayliner

-Maxxis RAZR MT tires

-60 gallon fuel capacity

James Langan

A version of this article was also published in the Turbo Diesel Register magazine.

Sources:

Cummins R2.8 Turbo Diesel

Proffitt’s Resurrection Land Cruisers

September 1, 2017January 14, 2019

Load Range F Toyos, a 1,700 mile evaluation

Toyo’s New Load Range ***F*** Open Country Tire Line

Toyo’s new load range *F* LT tires. Using ‘em hard.

Backgrounder

Torque, horsepower, and tow/haul ratings in our so-called light-trucks have been soaring toward the stratosphere for several years. The competition between the North American diesel pickup manufactures to one-up the other has never been stronger. They have passed the 900 lb-ft barrier and are marching toward the next big hurdle; 1,000 lb-ft of flywheel torque. (At least that is the number on-paper, torque management can make it feel like less, but the idea is to prevent unnecessary roughness and increase driveline longevity.)

In decades past the transmissions, brakes, frames, and other items didn’t match the grunt of the medium-duty truck engines stuffed into pickups, but those inadequacies are mostly behind us. The constant improvement of these components could not support the increased ratings if light-truck (LT) tire capacities didn’t keep pace. There is possibly nothing less safe than not having enough tire (capacity, speed ratings, etc.) for the job. Manufacturers continually strive to meet market demands. If we ask for and buy, companies are happy to build stuff for us.

More Air For Big Loads

There is science and some regulating body input that affects how much tires are rated to support. A simple way to think about tire capacities is to understand that it is the total amount of air inside a tire that supports the rated weight. That includes the physical volume/space inside the tire and the air-pressure. A tire of a given size that can accept higher pressures, is almost always going to be rated to carry more mass. More space and more psi equals more capacity in pounds.

As simple as we try to make this, there is at least one combination of ratings that many find illogical. Most, but not all, load range (LR) E LT rubber carry their maximum rated loads at 80 psi, but a few are rated for a maximum of 65 psi. In addition to not supporting as much cargo, because of the lower pressure, trucks with a simple TPMS (tire pressure monitoring system), like a late model 2500 Ram/Cummins, will always have a TPMS warning light illuminated when running with less than the maximum 80 psi in the rear tires and/or 60 psi up front.

The TRA Sets The Standards

The Tire and Rim Association (TRA) is the standardization body for this industry in the United States. It was established in 1903, and it is lead by top technical representatives from member companies. There are a few niche manufacturers who don’t belong to this association, and therefore may not abide by the industry standards, but they are few. The common tire sizes, load ratings, and capacities most of us use and are familiar with were created and sanctioned by the TRA. Traditionally, flotation sizes (33×12.50R17, 35×12.50R18, etc.) have received more conservative ratings, notably lower than those for LT-metric sizes. Why? Because the TRA says so. Maybe there is a technical and/or regulatory reason, but for the end user they are what they are, and we must pick a tire the meets our needs.

Load range *F* 35×12.50R18 handles 3,970# at 80 psi.

New Load Range F Toyo Tires

Toyo Tires is again leading the industry by introducing load range F tires in sizes that were formerly 65 psi, load range E. Toyo is making several in their Open Country A/T II and M/T designs, plus a couple for Open Country R/T. Toyo’s sister company Nitto was actually first to market with LR F light-truck rubber last year, but they are only offered in a few part numbers in one tread pattern, the Nitto Ridge Grappler.

Nearly all of the new LR F products added to the Open Country line are in flotation sizes, instead of LT-metric. Two 35” tall examples of these different size formats are the LT305/70R18 LT-metric, and the 35×12.50R18LT flotation size. Both are roughly 35” tall by 12.5” wide, and made for 18” wheels. All of the new Toyo LR F sizes listed here are for taller, 18”, 20”, and 22” wheels.

Open Country M/T

33X12.50R18LT

35X12.50R18LT

LT305/55R20

33X12.50R20LT

35X12.50R20LT

35X13.50R20LT

33X12.50R22LT

35X12.50R22LT

37X12.50R22LT

Open Country R/T

LT305/55R20

35X12.50R20LT

Open Country A/T II

33X12.50R18LT

35X12.50R18LT

33X12.50R20LT

35X12.50R20LT

35X13.50R20LT

33X12.50R22LT

35X12.50R22LT

37X12.50R22LT

Toyo A/T II Xtreme, 35×12.50R18, 68#, not yet mated to wheels.

Time To Think Differently About Tires. Use The Load Index

The load range letter designations will surely continue, but they are a somewhat confusing standard because the psi and LR are not married like most consumers think, they’re merely going steady but occasionally flirt around. The older ply rating (or P.R.) standard is still used, and this is stamped on the sidewalls of many tires (i.e. 6-ply rating = LR C, 8-ply rating = LR D, and 10-ply rating = LR E) and is arguably irrelevant in the 21st century. The numbers do not mean a tire has that many body plies; they don’t. This is a holdover from the old bias-ply days, where the number of cotton carcass (body) plies helped increase the capacity. Tire technology has advanced a bit over the past several decades, and cotton plies are no longer used. If the ply rating designations are outdated and the load range letters can be misleading or confusing, what should we use? One tire engineer acquaintance suggests we use the load index, and I’m inclined to agree.

Size, load index (128), speed rating (Q), and 12 ply rating.

The load index is a number that indicates the maximum weight a tire can support when properly inflated to its maximum cold psi, and it is stamped on the sidewall like the other ratings and information. Using the load index, and/or the tire inflation charts that I’ve favored for over 20 years, removes much of the potential confusion, as it focuses on how much is supported at what psi. My push to start using the load index over (or in addition to) these older metrics starts here. It will be an adjustment.

35X12.50R18LT Toyo Open Country A/T II Xtreme

My 2014, 25th Anniversary Cummins Turbo Diesel routinely operates at its GVWR, so I welcomed the additional capacity of the new load range F rubber. As a fan of shorter and narrower wheels, I chose the Open Country A/T II Xtreme pattern in a 35×12.50R18LT. With the new load range F/12-ply rating, each tire is rated to carry 3,970 pounds at 80 psi. The load index is 128, the speed rating is Q, tread depth is 17/32”, and each tire weighs 68 pounds.

For comparison, the 35×12.50R18 load range E A/T II has a load index of 123, which is 3,415 pounds at 65 psi. Increasing the maximum load by 555 pounds per tire is a big deal, and it is necessary for fans of big wheels and flotation sizes that haul heavy stuff.

The Xtreme Toyos have decent void for a 5-rib all-terrain.

Perfect Balance

Toyo prides itself on making exceptionally high-quality tires that often require relatively little wheel weight to balance. This is not just a claim; it has been confirmed by Toyos I’ve tested. Mounted on 32-pound Ram Laramie WBL aluminum wheels, the tread width is 10.25”, and the combination weighed 100.6 pounds on my shop scale. Using the dynamic, dual-plane balancing method, they took the following ounces to balance:

Outside Inside Total

#1 0.5 0.75 1.25

#2 2.0 0 2.0

#3 1.75 0.5 2.25

#4 2.00 1.5 3.50

“The New Dodge, America’s Truck Stop”, old-school measuring tool.

Dynamic balancing always requires more weight because the tires and wheels are balanced in two planes, vertical and horizontal, instead of just vertical (the so-called static method). For these tall, wide, and heavy tires and wheels to require so little lead is impressive. Four tries requiring so little weight is what one might hope for when using the static method for a smaller, lighter tire and wheel package. Even doubling the numbers here would not be unreasonable for static balancing. Awesome Toyo!

WBL Laramie wheels are slightly narrow, 8” vs. the 8.5” minimum recommended width for a 35×12.50R18 tire. They seem fine.

First Short Drives

Keeping the balancing data in-mind, it was no surprise that these Toyos were as smooth as glass at any speed on a good roadway. What about the difference between these new LR F Toyos compared to the same tire in a LR E? When I shared with friends I was running new LR F tires, a couple asked about the ride, assuming they would be stiff.

Ride feel is appropriate, no stiffer or sloppier than a typical LR E 80 psi tire. Running 60 psi in front and 80 psi in the rear—the same as most other tires and sizes on my Ram when fully loaded—the truck is as smooth and stable as it would be with any 80 psi tire.

The rugged and familiar 3-ply sidewalls and 7-ply tread of most Toyo Open Country LT designs felt just right. The obvious advantage of the new LR F is being able to carry more weight (load index 128) and not having a TPMS light illuminated when pumped-up to higher pressures.

Humboldt-Toiyabe National Forest, east of the Big Smoky Valley, Nevada.

Long Haul — A Quick 1,700 Miles

These new 35×12.50R18 Toyos were mounted just days before driving from Reno, Nevada, to Flagstaff, Arizona, for the Overland Expo West event. Driving conditions and surfaces included a little city, plenty of high-speed Interstate freeway, winding rural highways, some rain, dirt and gravel roads, and even a bit of snow.

The Toyo A/T II is mud + snow rated, and does well in snow.

The audible hum emanating from the Xtreme version of Toyo’s A/T II may surprise the uninitiated, but this 5-rib tread has a fairly open pattern for an all-terrain. The voids needed to help evacuate rain, snow, slush, moderate mud, and other debris, will make any tire louder than a less aggressive design. Of course the roadway surface makes a difference, tires typically sing more on concrete than asphalt, and the slightly wider (than I usually run) 12.5” meats put extra rubber on the road. The tires are not loud by traction tire standards, but you can hear them, and as I headed for the Southwest, the title track from Steve Earl’s 1986 debut album, Guitar Town, started playing on my radio, including:

“Hey pretty baby don’t you know it ain’t my fault

I love to hear the steel belts hummin’ on the asphalt…”

Being familiar with the tread, there were no surprises; the tires handled varied terrain well, as expected. I’ve run the Toyo A/T II Xtremes before, and was happy to evaluate them again.

James Langan

This article was also published in the Turbo Diesel Register magazine.

Sources:

Toyo Tires: toyotires.com

August 16, 2017

Overland Expo West 2017

Overland Expo West 2017 — Flagstaff’s Fort Tuthill County Park

New Venue

Overland Expo West is a three-day annual event focused on educating and inspiring folks to explore their outdoor world, both near and far. The big news for the event this year was change: it moved to a new venue, the Fort Tuthill County Park in Flagstaff, Arizona. The park offers about 30% more area and extra separation for truck and moto enthusiasts. There were over 200 classes, workshops, roundtable programs, and inspirational programs, as well as over 300 vendor booths. Fifty exhibitor spaces were added in 2017, with a waiting list for 2018, and there were about 2,000 additional attendees. The Overland Expo team is now focused on getting better, not bigger. Leading industry vendors and OEMs were present, including Ram and Cummins, which is where my coverage is focused.

Cummins’ R2.8 Turbo Diesel attracted much attention.

There can be growing pains… I did overhear someone saying that the general, dispersed-camping areas were too tight and full. My sense is that overall this was a good move for the Arizona event, the growing tribe of overland travel enthusiasts and the vendors that are happy to accommodate their desires for comfortable, vehicle-supported travels and camping.

New Legend 4×4 Meets The Cummins 2.8L

New Legend 4×4, based in Iowa, has been doing impeccable restorations of vintage Scout II and Scout 800 bodies, mounting them on modern chassis, complete with high-performance engines, to give enthusiasts the joy of driving beautiful vintage iron without the poor drivability of vehicles built 50 years ago. They work hard to maintain the original vibe and hard-working focus of the old wagons, while tastefully blending it with modern performance, reliability, and safety. New Legend 4×4 works with their clients to create the ultimate mix of a vintage/modern vehicle. These rigs are meant to be driven, not be garage queens.

I’ve been an International Harvester fan since my youth, partially because my great uncle Clarence had a few, plus I’ve owned a ‘60s two-wheel-drive half-ton and two Scout IIs. The first, a Scout Terra pickup, was my first four-wheel-drive. The New Legend Scout IIs with V8s were very nice, but the rig that made me gaga was this 1967 Scout 800 with a Cummins R2.8 under the hood.

1967 Scout 800 on a Jeep Wrangler chassis.

The FIRST Production R2.8 Turbo Diesel

The Turbo Diesel Register readership needs no explanation as to why one might prefer to repower vintage iron with the new R2.8 Turbo Diesel instead of a gas V8. New Legend 4×4 was one of 25 beta test shops for the Cummins R2.8L in the U.S., and thanks to Steve Sanders at Cummins, they were lucky enough to receive the first production version of this new crate engine just in time to complete this Scout 800 and drive it to Overland Expo. Yes, they drove it from Iowa to Arizona, essentially non-stop, swapping drivers, with lots of coffee and Red Bull, with the blessing and encouragement of their customer as part of the initial shakedown. I interviewed Luke from New Legend to get the details on this beautiful build.

The Cummins R2.8 swap looks factory perfect.

This is a 1967 Scout 800, the body is original but “freshened”, which means cleaned, repaired, and painted to high standards. It sits on a new Jeep Wrangler Rubicon chassis, with the excellent and proven OE Dana 44 axles with electric lockers both front and rear. New Legend wisely didn’t try to invent new Wrangler suspension, instead they use AEV’s proven 2.5” system, which maintains factory geometry and drivability. Luke said, “it drives and handles amazingly”, like a brand new Jeep Wrangler JK, because that’s what is underneath. New Legend teamed with Duluth Pack in Minnesota, because they love Duluth’s made-in-USA waxed canvas, which really helps this particular Scout retain a vintage, rugged look and feel. Just what the customer wanted.

Modified and updated, the interior still looks ‘correct’.

The Cummins R2.8 has it’s own ECM, and Cummins makes it incredibly easy to connect the engine to the donor chassis, essentially just fuel and a few wires. The flier for the R2.8 Turbo Diesel inline 4-cylinder says it produces 267 lb-ft @ 1,500-3,000 rpm, and 161 hp @ 3,600 rpm, with an asterisk indicating “final ratings may vary”. The motor is connected to a NV3550, 5-speed manual tranny, which is backed by an Advanced Adapters Atlas II twin-stick transfer case. The base price for a build similar to this is about $100k, depending on how the customer specs their new vintage four-wheel-drive. Cummins was a vendor at the 2017 Overland Expo West gathering, primarily to support this fantastic, small, light, and powerful little engine. Smart move, as the repower opportunities look promising in this market segment.

American Expedition Vehicles

American Expedition Vehicles (AEV) displayed their Prospector XL Tray Bed Edition, and the new Recruit, Ram 1500 package. The original Prospector XL was a personal project of AEV President, Dave Harriton, that was first displayed at the 2013 SEMA Show, and it has covered thousands of miles on- and off-highway since. AEV Special Operations is creating ten of these “Limited Edition, Unlimited Adventure” vehicles based on the regular-cab, long-bed, Ram 2500 platform. The trucks will feature their signature stamped-steel front bumper, DualSport suspension, lightweight aluminum bed, massive 41” tires, and more. The Prospector XL Tray Bed Package starts around $38,000, plus the base vehicle; I think they will sell all ten quickly.

The timing of this announcement is interesting, as I’ve been a fan of flatbeds since my commercial driving youth and my custom flatbed-equipped ’93 First Generation Turbo Diesel. For several months I’ve been trying to suppress my lust for a new regular cab, longbed truck…keep your eye on my column.

AEV’s Recruit package for 1500 Rams includes a new 4” DualSport suspension for these independent front suspension (IFS) trucks. It increases wheel travel and off-highway performance, while optimizing the steering geometry for improved handling and reduced driver fatigue on-highway. The A206 T4 cast aluminum steering knuckles, new tie-rod ends, AEV-spec Bilstein 5100 series struts and shocks are key ingredients. Under the truck, a stamped-steel 4mm skid plate offers serious protection and maximum ground clearance.

The 4” DualSport suspension include a cast aluminum steering knuckle and upgraded tie rod ends.

Perfect, tight fit for the Recruit’s skid plate.

The Recruit’s heavy-duty grille conversion facilitates mounting their existing HD front bumper. Cast aluminum tow loops instead of the ductile iron pieces reduce weight, and their Heat Reduction Hood helps the Recruit look similar to the Prospector. New 18” AEV wheels are more versatile than the common 20” OEM rims. The Recruit package starts at $15,000.

AT Overland Habitat Truck Topper

The ingenious and detail-oriented folks at AT Overland introduced a version of their Habitat camper for full-size Tundra, F-150, and Ram pickups with both 5.5’ and 6.5’ beds; it was previously only available for mid-size trucks. The Habitat fills the void between a basic truck topper and a slide-in camper. The shell is made with lightweight aluminum and composites, is very robust, and has a base weight of only 340 pounds. Easily opened by one person, the 15’ long tent that deploys provides 96” of standing headroom near the tailgate when mounted on a Ram, and 85” at the front; plenty. When standing outside on the ground, the bed above acts like an awning.

The tent is made from a very durable, Teflon-impregnated, waterproof ripstop nylon (285 grams-per-meter), by American tent and camping gear manufacturer, NEMO Equipment. If customers chose a base camper ($8,800) without optional cabinetry, stove, or refrigerator and such, the camper does not reduce the hauling area of the pickup bed. The Habitat pictured here is on AT Overland co-owner Mario Donovan’s 2017 Ram 2500.

AT Overland’s Habitat topper tent for full-size trucks.

Long and spacious inside a Habitat camper.

AeroContinental

AeroContinental has started making chassis-mounted truck campers featuring stressed skin construction that are designed to be both attractive and field-repairable. Their first effort was on a Ford Super Duty, but their second is more appealing to TDR-minded folks, as it’s mounted atop a 2017 Ram 3500 with AEV’s Prospector package. It’s just waiting for a customer to spec the final layout inside. It makes me think of a vintage Avion camper, or Airstream trailer. “Aerospace meets overland” is one of AeroContinental’s tag lines.

ARB USA

ARB had three new items on display that caught my attention. The coolest being their new Elements Fridge ($1,300), designed to survive tough duty outside, like in a pickup bed. This weatherproof 12-volt compressor refrigerator (not just a cooler) features a stainless steel body and hinges, a gas strut that holds the lid in any position, a pin-code lock plus padlock hole, a light, and more. Once you start using a real refrigerator for camping or tailgating, it’s hard to leave home without one.

The ARB Adventure Light 600 provides up to 600 lumens of LED light ($59), with a lower 300-lumen setting. This portable light can be recharged by both AC/DC power, includes a battery-level indicator, has hooks and magnets, and is dust and rain resistant. There’s little question it’s rugged; one of ARB’s press photos shows a truck driving over the light.

Appropriate tire pressures are critical for performance and safety. Modern TPMS provide a safety net, but the best maintenance practices involve frequent use of a quality tire gauge. ARB’s Digital Tire Inflator ($55) has 23.5”, PVC-covered braided steel hose with a push-on chuck and valve clip, which reduces the need to squat or bend over while filling tires. The backlit LCD readout is protected with a rubber guard; it’s designed to read from 1-200 psi (0-14 Bar, 0-1400 Kpa); there’s a bleeder button and a 200-hour runtime from the two provided AAA batteries.