TRD Tundra Wheels a 17 MPG Rock Warrior Solution?

Several weeks ago I posted about purchasing a set of OE 17-inch TRD wheels which included the original BF Goodrich All-Terrain 285/70R17 tires (17″ Tundra Wheels & BFG A/T Tires). However those were not the first, nor the best, set of TRD Rock Warrior wheels I have purchased. The Cooper S/T MAXX trial started last summer and has drug on for a while.

Cooper Discoverer S/T MAXX LT275/70R18E with Tundra SR5 18" wheel

The reasons for buying the 18-inch Tundra SR5 wheels was because I wasn’t enthralled with the fake beadlock rings on the Rock Warrior wheels (Goodbye Bling Rings), and because finding a set of  17-inch TRD second generation Tundra wheels for a reasonable price seemed nearly impossible. Most of the sets on Craig’s List were almost new, with almost new tires, and guys wanted almost new prices, upwards of $1,500 for the tires and wheels. No thanks. In addition to being far more than I was willing to spend, because I’m not a BFG A/T fan (not a hater, just not a fan) I really didn’t want to pay anything for BFG A/T take-off tires.

There were two issues with the 18-inch Cooper S/T MAXXs: the drifting to the right, and the stiff ride from the rugged, short sidewalls. I could seek alignment solutions for the pulling—which I doubted would work—but how could I soften the ride of the stiff, short sidewall tires without letting too much air out? The stout construction of the S/T MAXX appeals to me, there is a time and application for these tires and I wanted a set, but the 18-inch 275s were rougher that I cared to drive on.

After deciding I wasn’t going to keep the 275/70R18s, and to take advantage of Discount Tire’s excellent exchange policy, the question was exchange them for what? Another set of F-C II? That seemed a bit silly, since my existing set was almost new, and I’d rather have one set of mild treads and another more aggressive. Though I knew a second set of F-C II wasn’t going to pull to the right and wouldn’t be a waste of money. Since I’d been down this road several times with the 4Runner, I was confident I knew the unhappy ending.

Summer I80 Road Construction

The First Set of TRD 17-Inch Rock Warrior Wheels

Knowing my dissatisfaction with the 18-inch sidewalls, early one morning my friend Frank inquired about finding a second set of 17-inch TRD wheels. I quickly dismissed his idea, telling him via email I had looked and they were all too expensive… But I decided to look again, and hidden among all the ridiculously expensive was one reasonably priced set at an independent tire dealer in Sacramento, just a couple hours away (thank you Frank). I was the first person to contact the seller, told him I’d be there in a couple hours if he would hold them for me.

A rural road side trip in search of Dutch Bros. Coffee

Though there was summer road construction in the Sierras, and the several thousand vertical feet lost and gained during the 228 miles of travel, careful use of my right foot allowed the Tundra to squeeze 17.88 miles from each gallon.

TRD beadlock ring scuffing

The wheels were not perfect, but in hindsight they are the best set I’ve purchased thus far. There were a few scuffs on the fake beak lock rings from careless handling (which helped me to negotiate a lower price), and three of four spring clips that secure the center caps were missing, which I didn’t notice until I was home. But overall they were a very nice set the will likely stay with the Tundra as long as it lives in my barn.

TRD Rock Warrior 17-in. beadlock ring gouges.

TRD Tundra Rock Warrior 17-in. take-offs

With another set of 17s in the shop I didn’t know what I was going to exchange the S/T MAXX for, but I knew they were not going to be 18-inch tires.

Copyright © 2012 James Langan

Tire Pull Diagnosis

Looking For The Offending Tire 

Conventional wisdom regarding radial tire pull says that if a tire is the source of the pulling problem it can be diagnosed by using a specific procedure.

-Rotate the front tires side-to-side. If the vehicle goes in the opposite direction, it’s one of the front tires. If the vehicle goes in the same direction the pulling is from one of the rear tires, or is not a tire-related problem. There are more steps, but you can read them on The TireRack’s Pulling Tire Diagnosis PDF.

Though I have been through this procedure a few times before, I printed the PDF to insure I was following the steps exactly and made notes during the process. Guess what? The Tundra still pulled to the right, so I jumbled the position of the tires again and adjusted the tire pressure. Regardless of the position of the tires or PSI, the truck still drifted to the right rather quickly. So is there a chassis or alignment problem if there isn’t a tire problem?

Based on my experiences with my 4Runner I was quite confident that my alignment settings were fine, and not the source of the pulling problem, at least not directly. After numerous alignment adjustments attempting to redirect tire pull on the 4Runner (mostly cross-caster adjustments) some tires would still pull right while others would not. In fact depending on the tire and/or tread pattern, some tires required relatively high cross-caster while others needed very little. Using OE wheels, and in the case of the Tundra, OE sized tires, removes another variable that can make tire pull diagnosis difficult on modified vehicles. Are my modified chassis bent or broken, or are there simply compatibility issues with some tires and platforms?

Toyo M55 and Toyo M/T. Two tires that have caused tire pull on my 4Runner, but not on other trucks.

The Toyo M/T is known to cause a pull or drift on Dodge trucks, are these trucks broken too? My point is that even though the standard and accepted tire-pull diagnosis procedure might indicate the problem is not with the tires, that doesn’t mean there is a problem with the chassis. Having a second set of mounted and balanced tires has helped me confirm this a couple times. The tires may not be defective, but they may still cause a pulling problem on your truck and that doesn’t necessarily mean your truck is damaged or out of adjustment.

My favorite all-around tire remains the Dick Cepek F-C II. The Tundra’s alignment settings were working reasonably well with the F-C II and I was not willing to make changes that might improve the pulling with the S/T MAXXs at the cost of hurting drivability with the F-C IIs. Having two sets of tires isn’t practical if you need different alignment settings for each set.

What Next?

Copyright © 2012 James Langan

Alignment?

Now what?

Live with tire pull?

Look for a defective tire?

Change the alignment settings to suit the new Cooper S/T MAXX?

Suggestions?

On the alignment rack.

The process continues on Monday.

Copyright © 2012 James Langan

Cooper S/T MAXX LT275/70R18E Part 2

A Minor Lift

All thirty-threes are not created equal, because they’re not all exactly thirty-three inches tall. The very common 285s are typically 32.8-inches tall while 255/85R16s are almost always 33.3+ inches; the Toyo M/T is 33.5-inches! Removing the Dick Cepek F-C II 17-inch 285s, slapping-on the 18-inch Cooper S/T MAXXs, and taking a few measurements showed that the taller 275/70R18 MAXXs were good for 3/16″ of additional clearance under the rear differential. Nice.

My initial S/T MAXX drive was on a test loop I typically travel after any tire, wheel, air pressure, alignment, or other drivability changes are implemented. It’s several miles long and includes city streets, rural highway, interstate freeway, and sometimes just a minuscule amount of dirt for photos. The route and terrain are familiar, as is the vehicle platform, what’s being evaluated is the change, in this case, tires.

LT275/70R18E Cooper S/T MAXX, slightly taller than most 285s.

Noise

What noise? Articulating tire noise can be a challenge, as vehicles have different levels of insulation and sound deadening, and drivers have their biases and tolerance or lack thereof for noise. With several back-to-back tire tests under my belt the S/T MAXX is clearly one of the quietest traction tires I’ve ever had the pleasure to drive on. The volume and tone is similar to my beloved Dick Cepek F-C II, but a bit quieter, and the MAXX is certainly quieter than the standard Cooper S/T. Comparing the S/T MAXX to the super popular BF Goodrich A/T is tough. While I currently have a set of used BFG A/Ts, I have few personal miles on them and I’m not a BFG A/T fan. I’ll go out on a strong limb and say the new S/T MAXXs are louder than the BFG A/T, but not much. For a tire that offers as much traction and void (much more than the BF Goodrich A/T) the Cooper S/T MAXX is an amazingly quiet tire and well worth the little noise it makes.

LT275/70R18 S/T MAXX on Tundra SR5 wheel

Stiff 

As noted in my introduction, the ArmorTek3® carcass construction and 3-ply sidewalls of the S/T MAXX are stiff. This can be great if this is a feature you are looking for, or a negative if you prefer a more compliant ride and/or a lighter tire. (If you are new to this blog or subject, read Wheels, Tires, and Sidewalls from Jan. 30, 2012.) In addition to the intentionally rugged design of the S/T MAXX, using 18-inch wheels with only a 33-inch tire adds to the lack of sidewall flex.

One of my strong dislikes for tall wheels on light-trucks is manifested by this situation: a relatively tall tire (33+), with a relatively short sidewall doesn’t offer the same off-highway flex and performance available from a taller sidewall. The same height tire on a 16-inch rim would yield an additional inch of sidewall to drive and flex on; this is not a small difference. If you already use and like the firmness of a load-range E sidewalls then the stiffness of the S/T MAXX (similar to the Toyo M/T) may not bother you, particularly if you don’t have to run it on a tall wheel. However, if you prefer a more compliant ride or a lighter tire you might reconsider the MAXX. What do you want, and what do you need for your application?

S/T MAXX with Old Man Emu (OME) suspension.

Pulling To The Right 

Several years ago I rarely experienced tire pull problems with my trucks, however they are all live-axle 4WDs. Starting with my 2006 V8 4Runner and now continuing with this Tundra, I’ve experienced a pull (or drift) to the right with certain tires but not with others. Both of these IFS four-wheel-drives have alignment settings and geometry that are equal to or better than when new.

Aftermarket upper-control-arms are employed and expertly adjusted, though invariably some tires cause a very noticeable drift or pull to the right. I’ve spent countless hours and dollars to try and understand, identify, and combat this situation on these Toyota 4WDs. In short, my work involved many trial-and-error alignment adjustments, tire & wheels swaps, rotations, and tire pressure changes, all of which did not correct the problem. Some tires would still pull right, some terribly so.

How bad is the pull or drift? On a straight section of freeway with little road crown, at 65 miles-per-hour, releasing the steering wheel will result in crossing the right lane-line in about 3-seconds. Three seconds! I’m a strong advocate of keeping one, if not two hands on the wheel, and paying attention to the task at hand when driving. But I also like my vehicles to have very neutral handling, heading straight down the road unless instructed otherwise. Modified or not, I require my vehicles to drive almost perfectly on-highway. For comparison, depending on the road, wind, and other variables, with the same alignment settings Dick Cepek F-C II tires would continue straight for 8–10 seconds with no-hands.

Some readers may observe that the wheels are not identical. OE 17-inch forged TRD wheels are being used for the F-C II, while the MAXXs are mounted on 18-inch SR5 wheels, and there is probably a slight difference in backspacing. Is that part of the problem? I doubt it, though I did consider of this difference, and have a plan.

After an interlude, there will be more Cooper S/T MAXX commentary in the future—first we have to drive there.

S/T MAXX 275s on the Tundra

RoadTraveler.net – Rollin’ Forward

Copyright © 2012 James Langan


Cooper S/T MAXX LT275/70R18E Preview (Traction Tire Part 2)

The Cooper S/T MAXX 

After deciding the LT275/70R18 was my perfect 33-inch tire for an 18-inch wheel, and seeing there is a nice selection of tires in this size, a tread had to be chosen. This was relatively easy as I’m familiar with most of the popular light-truck traction tires. I’m a fan of Cooper Tires and their subsidiaries, and the new S/T MAXX design was already on my to try list, offering the type of any-terrain tire I prefer—not too biased toward on or off-highway. Cooper calls this a 50/50 tire (on/off pavement) and I’d say they are very close to hitting that mark.

LT275/70R18E Cooper S/T MAXX

After some online shopping, my local Discount Tire matched a price from TireCrawler, a mere $242 each delivered. (This was a few months ago; tire prices change, usually increasing.) Discount ordered the tires and a few days later I hauled my 18-inch wheels to their shop for mounting and balancing. Cooper says the LT275/70R18E MAXXs are 33.35 x 11.2 inches and my scale said they weigh 60.5-pounds each. Combined with the relatively heavy, 30-pound, 18-inch cast aluminum SR5 Tundra rims, each tire/wheel combo weighed 91-pounds!

Stout Construction

Once you get your hands on one, there will be no doubt the S/T MAXX is a super stout tire. The scale tells part of the story, though not all load-range E or 3-ply sidewall tires are created equal (see Wheels, Tires, and Sidewalls). Grab an unmounted ArmorTek3® sidewall and give it a good jerk back and forth, they’re stiff, similar the Toyo MT, and more substantial than the 3-ply sidewalls on the very common BFG All-Terrain. The MAXX sidewalls are much stiffer than the older and lighter-duty Cooper S/T, which offers flexible sidewalls and very little sidewall tread. Similar name, and I like both treads depending on the intended application, but they are very different tires. Try not to confuse the S/T MAXX with the S/T, or the Cooper STT… maybe Cooper needs some new letters?

The S/T MAXX has beefy sidewall lugs/tread.

The S/T MAXX is an impressive looking tire. The sidewall lugs are attractive and thick, more impressive in person than in the photos I’d seen, and possibly the most aggressive sidewalls I’ve seen on a tire in this class (not a mud-terrain). The tread is a hybrid 4–5 rib design with a bit less void than the older 4-rib S/T, the center circumferential groove is noticeably missing. There is a moderate amount of siping and the cut & chip resistant compound is studdable. Cooper describes the MAXX as a “commercial grade traction tire”, an accurate description.

S/T MAXX 4-5 rib hybrid tread design.

Mount & Balance 

Mounting a 275/70R18 S/T MAXX on Tundra 18 inch SR5 aluminum wheel.

Mounting the first tire and giving it a spin on the balancer showed it wanted 3.25-oz. inside and 4.75-oz. outside for a dynamic balance. Eight ounces is not much weight for a 91-pound spinning mass, but I generally like to add less weight to my wheels when possible.

While dynamic balancing is the technically the best as it balances in two planes, I’ve had many positive experiences using the single plane static balance method for heavy RV tires (an old term). Static spin balancing counters vertical imbalance (hop) of a tire & wheel, and I don’t run very wide tires where dynamic balancing can be more important. Generally, I see how the first couple tires in a set balance and if they can be dynamically balanced with moderate weight, that’s what we do. If they are going to ask for substantial weight using the dynamic method, I choose static.

Modern balancing machines are very good.

Sometimes this difference can be very dramatic. A few months ago a heavy, high-quality tire wanted about 9 ounces for a dynamic balance, but only 1.5 ounces for a static balance. Guess which one I chose? The S/T MAXXs were single pane balanced and the road force (RF) was also measured—which was very low—another indication of quality. For more thoughts on tire balancing you can read Static Balance Details.

Static Balance Numbers

#1) 4.75-oz. RF .002″.

After seeing this low road force number the kid doing the balancing commented “Wow, that’s like a Michelin.”

#2) 4.25-oz. RF .008″

#3) 5.50-oz. RF .007″

#4) 1.50-oz. RF .009″

Cooper Tires’ website lists the tread depth for every S/T MAXX currently made as 18.5/32″, which it probably is. But it would be pretty easy to call this 19/32″ as measuring down to one-sixty-fourth can be a challenge. The original tread depth is important, more is better for most truck tires, though the long-term wear rate is also important. Combine deep tread with a low rate of wear and you have a long-lasting tire.

LT275/70R18E COOPER S/T MAXX tread depth.

Because my original 17-inch Tundra TRD wheels use tapered lug nuts, which are uncommon for modern Toyota trucks, I needed new shank-style nuts for the 18-inch wheels. Searching online I found a source for the Gorilla brand lug nuts and locks, a complete set was delivered for about $110. I’ve been using an impact-gun on Gorilla wheel locks on my 4Runner for years, and they have held up to my intense use. I wish they would fit on the OE 17-inch TRD Tundra wheels.

Shank style Gorilla locking lug nuts needed for SR5 wheels.

Driving Impressions

To be continued…

Copyright © 2012 James Langan


Traction Tire Preview Prelude

For several years I’ve been a fan of what are often called aggressive all-terrain tires. Labels and classifications can be difficult, sometimes neither descriptive nor adequate as there is much crossover, gray-area, and blurred lines with tread designs. These tires are not as open as a mud tire, but offer much more void than the typical all-terrain or all-season tire. Current examples include Mickey Thompson ATZ 4-rib, Dick Cepek F-C II, Cooper S/T Maxx, Goodyear DuraTrac, Dean SXT Mud Terrain/Cooper S/T, and the Toyo M55. These treads are also called traction or commercial traction designs.

Limited Terrain SUV Tires

When marketing types decided that utility vehicle was no longer an adequate description for 4WD utility wagons, the Sport Utility Vehicle (SUV) appeared, surged, then dominated the light-truck utility market. Lighter-duty all-terrain tires that offered less void and less traction became popular on the increasingly soft SUVs over the past two decades. It’s understandable that SUV tires became so road-biased, as invariably that’s where many log all their miles in their SUV trucks, but many of these conservative “all-terrain” treads would be more accurately described as all-season tires.

Michelin Cross Terrain SUV tire, properly labeled an all-season highway tire.

Despite the 4WD SUV becoming the modern on-highway station wagon for much of the U.S. if not most of North America, there are still those that want their 4WD wagons to be body-on-frame truck designs, shod with better, higher void traction tires. These folks include hunters, sportsmen, off-highway adventurers, people who live or work in rural areas, and those who travel in serve climates. For a variety of reasons a mud terrain tire may not be preferred (less MPG, longevity, and less traction on wet roads, with more noise) but a low void all-season tire labeled and masquerading as an all-terrain often doesn’t do the job either.

More void is desirable to absorb debris and let it escape. The wetter the material the more void you might want, and open, lug designs are typically louder, though modern tire design has reduced the noise penalty for some traction tires.

Toyo M55 & Multi-Mile TXR LT255/85R16D

What Size

I’ve never been a fan of needlessly wide tires, but wide tires have dominated the enthusiast 4×4 truck aftermarket for several years. Fat tires work well for some applications, but have many limitations for common usage, particularly on-pavement, where even the most active off-highway explorers travel thousands of miles each year. A slight correction seems to have occurred, where not every enthusiast 4×4 tire needs to be over 12-inches wide; 285 mm wide tires have caught on.

While I’m currently using and have accepted 285s, in my mind they are still a bit wide, roughly 11.5-inches depending on the tire—narrower tires track straighter and offer better MPG. Drivers are at least aware of fuel economy because of the cost of fuel, though I don’t see many people driving for fuel economy, bad habits are prevalent and it seems we’re often in a hurry.

The days of much narrower 33-inch enthusiasts tires like the LT255/85R16 are disappearing fast. Thankfully, if you don’t want such a tall tire, there are many 235–265 mm wide treads in the 31–32-inch range that can deliver better fuel economy.

Great traction tires: LT255/85R16D Cooper S/T & LT285/75R16D Dick Cepek F-C II

Eighteen Inch 33s

Not knowing much about 18-inch tires or wheels, but owning a set of take-off eighteens, I studied the options and was pleasantly surprised to discover the LT275/70R18 size. This size is just slightly narrower than the common 285 mm treads in either a 16, 17, or 18-inch, but with a reasonable aspect ratio of 70 percent. Most 275/70R18s are 33.3-inches tall, very similar to the tall 255/85R16 size that I’ve loved for fifteen years.

Eighteen-inch wheels are two inches taller overall, so tire sidewalls are a full inch shorter at the bottom (the part we feel and drive on). Historically 255/85R16s were flexible and pleasant riding load-range D designs, though load-range E is becoming more common in a 255/85, but 275/70R18s are almost all load-range E rated. Not all load-range D or E tires are created equal, some are stiffer than others, but shorter load-range E sidewalls on a 275/70R18 are going to be stiffer in almost every application. Again, stiff sidewalls can be a positive or a negative, depending on your needs and preferences, refer to this Wheels, Tires, and Sidewalls article for more on this subject.

To be continued…

Copyright © 2012 James Langan