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

LT255/85R16 Tire Delivery Part 3

Long before my route was paved there were much hardier travelers who passed this way. I stopped for a brief photo and took a moment to reflect. Lately I’ve been reflecting on how thoroughly spoiled we are with easy, efficient, convenient long distance travel. Several decades ago vehicles were not as low-maintenance and relatively trouble-free as they are now. Before the transcontinental railroad, traveling across The States was a serious, life-threatening endeavor. As modern motorized backcountry travelers there is always the possibility that our machines and computers will fail and we will be reunited with primal overland travel; walking.

Beckwourth Trail

Below is a poor grab shot through windshield glare and at a substantial distance  as I drove through the small town of Quincy, California. It’s not everyday that one sees an nicely restored original Bronco with uncut rear fenders, and nice, narrow original size tires.

First Generation Classic Ford Bronco, uncut fenders and small, narrow tires.

Onward further into the country where I met Brian and his family—very kind people. Brian and I visited for over an hour, talking mostly about trucks and tires, before I started reversing my path.

After several miles I drove down a dirt road where I enjoyed lunch. I really like having a tailgate for picnics, one of the advantages of a pickup over most utility vehicles.

 

Excellent Highway Fuel Economy

After lunch and enjoying the sights and smells of the forest, my fuel economy mission resumed. Theoretically, there are many ways in which to improve fuel economy. Though if your vehicle is outfitted the way you like it and your maintenance is up-to-date, the best way to increase fuel economy is to drive slower and pay attention to your driving technique—there is more to it than simply lowering your top speed.

My not-so-speedy-delivery was a 183.7-mile all highway roundtrip, on which the 3UR-FE 5.7L aluminum Toyota V8 consumed 9.761 gallons of gasoline. The math says that’s 18.81 miles-per-gallon. Excellent.

I’d love to attain this type of economy all the time, but mixed driving, living at altitude, and driving up and down mountains makes it nearly impossible. Though for a lifted truck with a big gasoline-powered V8 engine, and reasonably large & wide 33-inch LT285/70R17D tires (Dick Cepek F-C II), being able to top 18 miles-per-gallon is an accomplishment. Some of the credit has to go to the very tall sixth gear overdrive, which lets the engine lope at very low revolutions-per-minute when lightly loaded, and use little fuel.

Road Traveler – Rollin’ Forward and Sippin’ Fuel

Copyright © 2012 James Langan

LT255/85R16 Tire Delivery Part 2

With a bed and trailer full of tires & wheels I was off to see my tire guys for dismounting, mounting, and balancing so I could get my 4WDs off jack stands and rolling again. A few days later I loaded the bed of the Tundra with the Bighorns and Cooper S/T treads, as well as one old Multi-Mile Wild Country TXR so Brian would have a proper 255/85 spare.

Years ago the TXR was a big seller for the western tire chain Les Schwab. I really liked the void ratio of the TXR—not an A/T nor an M/T—and I purchased a few sets over several years. However, they were not the most rugged tire and tended to cause a steering wheel wobble. The last rig I ran the TXR on was my 2005 Wrangler, which was not as tolerant of their idiosyncrasies, so I moved on to better tires…and have yet to stop.

A load of LT255/85R16D tires, a Multi Mile TXR in the foreground.

I had a few goals for this little trip; deliver the tires, meet my new friend Brian, enjoy a country drive, and conduct a mileage test. After fueling at my local filling station and resetting the trip meter, it was time to roll with a goal of keeping my speed at 65 mph or less.

Through the cities and into the fertile Sierra Valley I drove. It cost, but one of the features I enjoy on the new Tundra is the satellite radio. There are a few stations I like, but I seem to listen to Outlaw Country often, Steve Earle came on singin’ Hillbilly Highway.

Copyright © 2012 James Langan

LT255/85R16 Tire Delivery Part 1

Stranger Danger Online

The world may be full of dangerous people, and jokes about meeting people “on the internet” can ring true when you hear a horror story or two. However, there are lots of very honest, honorable, and friendly people in the world, and many of them are online—just like the rest of us.

Is Mr. 255/85 Selling His 255s?

I received a note from a guy named Brian asking specific questions about the LT255/85R16 tire size. After a few emails I decided he was a nice family man and agreed to sell him two sets tires, which I’d been contemplating selling for a while. These sets, one of Maxxis Bighorns and another the Cooper S/T, were used but still had about 14/32 of tread remaining.

I’ve been a user and advocate of the 255/85 size since purchasing my first set in 1998, but I have been using more 285s, mostly because there are many more tread choices. There just are not that many 255s made these days, and some of the better, tougher, and longer wearing designs don’t track well on my 4Runner, further limiting my options. The 255/85 is still a great size, I’ll likely never stop singing the praises of this 33×10″ tire, they’re still what I prefer running on my F350.

Cooper S/T 255/85R16D, Cooper S/T MAXX 275/70R18E, Dick Cepek F-C II 285/75R16D

By rural western standards Brian lived nearby, about 80 miles, but had a very busy work schedule that was going to prevent us from meeting for several weeks. I offered to deliver the tires if he paid for my fuel.

Tire Swap Fest

The Maxxis Bighorn 255/85 tires I sold were still mounted and being used on my F350. The Cooper S/T treads were mounted on a spare set of TRD FJ Cruiser wheels for the Mall Crawler. Selling these required lots of tire changing and even some tire purchases but it will take me a few posts to share the whole story. Imagine that, James buying and testing tires. Though buying and swappin’ tires is much easier and less expensive than swappin’ women—just sayin’.

Pulling the Maxxis Bighorns from the F350’s OE forged aluminum wheels meant I needed to fit something else. I robbed the set of Dick Cepek F-C II in LT285/75R16D from the Mall Crawlin’ 4Runner and ordered replacements…

Stuff is missin'

Copyright © 2012 James Langan