Cooper Tires’ Discoverer S/T MAXX has been my favorite commercial traction/hybrid tread design since its introduction. I have experimented with four sizes on four different truck platforms, and suggested them to many friends and acquaintances. Two of my four-wheel-drives are still running the S/T MAXX, including the built, 2006 V-8 Toyota 4Runner with 4.88:1 gears in this video.
After a whopping 7,436 miles before the first rotation, mostly road miles, these LT285/75R16 Discoverer S/T MAXX are wearing impressively well and evenly. From their original, generous depth of 18.5/32″, the fronts are down to 16/32″, and the rears 16.5/32″, 2.5 and 2/32″ respectively. That’s an average of 3,300 miles per 1/32″ of tread, and excellent wear from a fairly aggressive, moderate-void tire on a full-time four-wheel-drive car. They were rotated using the rearward cross pattern.
With all my posts about tires it’s not surprising that I receive mail asking for opinions and advice on tires. A gentleman named Guy from Washington recently asked for my input. Below are his questions and my replies. My review and comments on the 255/85R16 Toyo M/T on my old F-350 will continue.
Howdy, hope you can help me a bit with a tire selection dilemma: 2012 two-door JK, that I use as a daily driver here in Wenatchee, Washington. Also do a couple of road trips every year, 2000 – 3000 miles each. Hunting. Fishing. Some overlanding. Did the 600 mile WABDR this past summer. I’d like to use the same tires all year, snow, rain, heat.
The two-door JK is a nice platform, I was shopping Jeep JKs online just a few days ago, including the two-door models. Sounds like your Jeep sees a nice mix of uses. As much as I’m a tire aficionado who tests and often owns more than one set of tires for a particular platform, there are advantages to picking a set of all-around treads and using them until they’re ready to be replaced.
Very basic Jeep. Manual transmission, 4.10 gears, aftermarket air lockers front & rear. 1.5″ Teraflex leveling kit (springs).
Sounds nicely set-up. There’s much to be said for lower lifts, and I love manual transmissions. Aftermarket selectable air lockers, presumably ARB Air Lockers, are accessories that offer a level of control over traction and wheel rotation that is only available with selectable lockers.
I bought a set of used 16×9″ rims and E-rated 265/75/16 BFG AT’s a week or two after I got the Jeep. Killer deal, $1k for five rims and tires. I’ve put another 25,000 miles on those tires, and they’re getting worn. So I need tires soon. I could just replace them with more 265’s, but they’re a little short.
Several years ago the first aftermarket tires I put on my V8 4Runner were 265/75R16. I agree that 265s are a bit short, most are notably smaller than 32-inches tall. Depending on the tire and tread chosen and the actual height, the advantages to stepping up to a 33-inch-tall tire are quite noticeable. Even with a short thirty-three (32.8″) the approximately one-inch in overall diameter will lift your Jeep a solid half-inch, everywhere. The best lift is tire lift.
I like the 255’s, roughly 33×10’s. Nice! But, I’m afraid they won’t work with my 16×9’s.
You are correct, in addition to being too wide according to the tire manufactures, a 9-inch wheel is a poor choice for a 255 tire for our uses, while a 7–8 inch wheel would be prefect. A 9-inch wheel is also wide for a 265, I prefer to run a 265/7x tire on a stock 7–8 inch wheel. I’ve not shopped for Jeep wheels recently, but I’d image there are many high-quality, original equipment, aluminum take-off wheels for sale on Craigslist. I’ve been a huge fan of the 255/85 size since the early 1990s and have been using them steadily on at least one of my four-wheel-drives since 1998.
Simple solution is just 285’s, but… I fear that’s an awful lot of tire for a little two-door JK… Maybe ditch the 16×9 wheels? I do like the way they look, but I could swap to a more narrow wheel & tire combo happily.
Surely 285s will work on your 9-inch wheels and that is a simple solution. Tread choices in 285/75R16 are almost endless. However, I’m not a fan of using wheels that are on the wide end of specifications. For 285s I prefer to run a 7.5-inch (the minimum) or 8-inch wheel, both for how the tire fits the wheel and the narrower overall width. I don’t care for tires and wheels that protrude further than necessary. I’ve run a few sets of 285 tires over the past several years out of necessity or a desire to run a particular tread that was not available in a 255, but I’d almost always prefer a 255/8x if I could get what I’m looking for.
Ditching the 9-inch-wide wheels would be my suggestion regardless of what tire you purchase. Choosing wheels that are at least 7.5-inches wide but no wider than 8-inches, will allow you run any of the tire sizes we are discussing here; 265/75R16, 255/85R/16, or 285/75R16.
Have four heavy-duty old style tire chains that are a little big on 265’s and fit 285’s real snug.
One old set of tire chains I have fit both 265/75 and 255/85 tires similarly, I believe both tire sizes use the same chains. My chains are too small for 285s.
And of course I haven’t quite made up my mind re tire type either. The AT’s have done surprisingly well, but I find myself looking hard at the Toyo MT’s and Mickey Thompson MT’s. My son runs 33×12.50 Mickey Thompsons – and they’re terrific off-road, but I’m not that impressed with them on pavement.
When I finish telling the story of using the Toyo M/T on my F-350 the rapid wear might surprise a few readers. I’m a fan of Toyo tires, but when I can, I much prefer a tire that will offer less noise and longer wear. Of course tire wear is often specific to the platform, driver, and use.
There are a set of Mickey Thompson MTZ tires sitting in my shop mounted and ready for use on my Tundra, but have only seen about 2,000 miles of travel. I like them, but I’ve preferred the Dick Cepek FC-II treads I’ve been running for most of the Tundra’s miles. The FC-II (replaced by the Fun Country) has less noise, excellent siping, and have been slow to show wear on everything from an F-350 diesel, the Tundra, and a built V8 4Runner. Of course neither the Fun Country nor the Mickey Thompson MTZ tread are available in the 255/85R16 size.
The biggest decision you have to make is tire size. If you chose either a 265/75 or 285/75 your choices are many, both a blessing and a curse. If you decide to try a set of 255/85R16 rubber, then it will be relatively easy because the choices are relatively few.
If the 255 size wins, and you decide you don’t want a loud or faster wearing mud-terrain tire (Maxxis Bighorn, Toyo M/T, or BFG KM2), I’d suggest you consider a set of Cooper S/T MAXX. The S/T MAXX has only been manufactured in the 255/85R16 size since the first quarter of 2014. I’m currently running a set in the 255/80R17 size on my 4Runner.
Will The Most Efficient Tires Please Drive Forward
It’s often stated that narrower, lighter, less aggressive tires are more efficient and will yield better fuel economy, but how much better? To properly compare apples and pears one must take care to reduce the variables that are always present during real-world tests. In this case I used the same vehicle, same gas pump, during similar weather conditions and time of day, calculated the odometer error, and used the same section of freeway. The GPS-confirmed road speed was 64-MPH and was maintained by cruise control. The tires were inflated to 35-PSI in all but the last test with the Dick Cepek F-C II treads where I goofed and only used 32-PSI. The F-C II tires performed so well I doubt they could have provided better economy with an extra 3-PSI.
If you think the fuel economy numbers listed below are too high you are partly correct, the tests involved almost zero city driving. The variables of in-town driving are not repeatable and won’t yield consistent data. What these tests do show is the fuel economy potential of this vehicle and establishes a baseline against which other tests can be measured. For each test the modified 2006 4.7L V8 4Runner was fueled and then driven a few blocks to the same freeway onramp, onward to a specific exit, and then the route was reversed and terminated at the same gas pump where the engine was promptly turned off.
All the tires used were close to the same diameter, about 33-inches, and they were all mounted on Toyota FJ Cruiser TRD 16 x 7.5-inch aluminum wheels. Because of the slight differences I tire height, one corrected odometer reading of 56.76-miles was used for all the tests. Listed below with the figures are the weights of each tire/wheel combination.
Cooper S/T LT255/85R16D: 75-lb 3.027-gal. = 18.75 MPG
TreadWright Guard Dog LT285/75R16E: 87-lb 3.331-gal. = 17.04 MPG
Dick Cepek F-C II LT285/75R16D: 83-lb 3.121-gal. = 18.18 MPG
I was a little surprised that the very narrow and light Coopers consumed more fuel than the heavier, more aggressive Maxxis Bighorns. Though when filling-up after the Cooper test the gas-pump didn’t stop normally and a little gas spit from the filler, possibly contributing to the lower reading. Longer distance tests would likely be more accurate, but this type of testing is very time consuming and expensive.
It was expected that the heavier, wider TreadWright Guard Dogs with their aggressive lug tread would use more fuel. The Cepek F-C II tires impressed me by splitting the difference and topping eighteen MPG!
Surely tread design, width, and weight all make a difference. My theory is that width and tread design have a larger impact on fuel economy than tire weight, at least when there is only a few pounds difference. There is five pounds separating the Maxxis Bighorn 255/85R16 and TreadWright 285/75R16, but I don’t think those additional few pounds account for the 1.77 mile-per-gallon difference. There is a seven pound difference between the Maxxis Bighorns and Cooper S/Ts, but the results for these two 255s were so close you could call it a tie.
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.
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…
Several weeks ago I cut a sidewall on one of my LT285/75R16 Dick Cepek Fun Country II (FC II) tires. The story about the sidewall cut and trail will be told later, but with only three FC II treads on the 4Runner I was in need of at least one new tire. Since I had been running a close enough 255/85R16 spare, I decided to buy two FC II to insure I had the exact tire in the unlikely event I ruined another casing in the near future. My calculations indicated that if I rotated the older three tires on one side of the car, all with 3/32″ of wear, and the two new ones on the other side, the wear would even out over the next 30,000-miles.
Most tire warranties don’t cover off-road use. This is term is open to interpretation, as many state and county roads in the rural west are not paved but are still very clearly roads. Regardless, since the three older FC II treads had been purchased mail-order and were not covered under any road hazard warranty, I decided to buy the new tries mail-order as well. One of the local tire shops I do lots of business with would have mounted & balanced the new treads for a reasonable fee, but I decided to play with a little old school technology and balance them myself. It wasn’t easy.