Another tire thread? 285 vs 255 pros and cons?

[tromz]

Hey folk's getting ready to upgrade. Pretty much decided on Km 2s . Can anyone post and relevant cons to that tire? The rig is mostly my DD . My milage is less than 20 a day,but It still spends some time off highyway in low traction environments. I do wheel it also. Its currently stock ,locked,slidered,skided , de flared scratched and the 'ol right rear quarter dent. I'll probably eventually go up to 35s and a regear cause downhill sucks!! Just wondering pros and cons on the different sizes of "33"s . All the info gave me a headache. Jee some are 32s some are bigger than 33s some 35s are actually 34s. Just wondering the benefits of the skinnies vs the others really. I live in Virginia and wheel out east . Where I live the woods get slick.
Thanks for the imput in advance folks!!

 

[profro]

I have 255 KM2s and the biggest pro was they were cheaper than the 285 version. All other pros and cons are debatable. I would say this I wouldn't like them as a daily driver. Id hate to waste all that rubber and tread depth on concrete.

 

[tromz]

willing to deal with the drop in road manners. It is my understanding that the Km2 is closer to a A/t than some . And I hate goodyear so not an option. I have my reasons. I wanna wheel a little more and I dont drive around a whole lot at home . Most trips are under 10 miles but I would put in some highway time to the trail head. Further comments?

 

[Douglas S]

I think I'm going to run the 285/75R17's (~34x11.5) on my truck. Seems like the perfect size for a mild lift (2.5").

What diameter are your wheels?

 

[tromz]

oops I'm on the stock alloys. 16 inch. no lift yet.

 

[maybe_a_80...]

Unless you have a compelling personal aesthetic-, performance, or overall build strategy- reason to run the 255/85 tire size, get 285/75 tire size.

We never hear of anyone having traction issues with 285/75s. We never hear of those with 255/85 having traction issues either, but there are some who feel strongly that less rubber on the road is a detraction. Truth be told, there are some scientifically proven benefits to the longer, narrower tread pattern of the 255/85, but at some point it's just picking hairs over tires that are roughly the same diameter and have different track widths.

If you want to dive into the benefits of the 255/85, read the thread on the Expedition Portal Form - Cooper ST's - 255/85/16.

If you want to dive even further, there is a white paper link buried somewhere in the thread linked above.

Personally, I am a fan of the 255/85 tire. It is more of a "world" look than a "U.S." look, and tall skinny tires are preferred the world over for expedition type rigs for their general efficiency and ability to provide clearance at the axle. It's also interesting to note that Jeep specs many of their rigs stock with a 255 aspect ratio tire, and for what it's worth, Jeep does know a thing or two about off road.

I'd really like to put some 255/85s on my truck. Except that I live in a place where having a superior snow traction tread is imperative. And short of the Trxus M/T, there is not a 255/85 out there with this type of tread. The Trxus might do the trick and end up on the truck when it's time for new rubber. But it's hard to argue with the absolute plethora of great tires available in 285/75.

Good luck!

 

[tromz]

Seems as though listings are cheaper at sams for the 255 ...both sizes special order. Where do I find the best prices. 1500 bucks is steep...282 a tire plus mounting.

 

[shermantank55]

Tire Prices

$190/tire online at Tire Rack for 255/85:
BFGoodrich Mud-Terrain T/A KM2
$246/tire for 285/75
BFGoodrich Mud-Terrain T/A KM2

I have the 255s and have been very satisfied with them both on and off road. I have OME 2.5" lift. I am partial to the skinnier tires as well.

 

[Gfresh]

Pretty much decided on Km 2s . Can anyone post and relevant cons to that tire? The rig is mostly my DD.

Where I live the woods get slick.

KM2 cons are that you do get a slight tire noise from about 30 - 55mph. From 55mph and up, it is definitely a noticeable hum. On the order of the wind noise due to the vehicle itself. My LX450 is not a DD. So, it's tolerable to wife and I. Lower tire pressure (around 30psi) decreases the noise. I run mine at 40+ psi on the highway for better fuel efficiency...

The pros are the mud performance (should not be a shocking statement). My brother and I were on slick, clay-type mud in Copper Canyon, Mexico. He was in my old '97 4Runner running BFG AT (285's) with 2/3 left on the tread. I was on the 255 KM2's. Both were on 16" wheels and are 33" diameter.

I was leading and he slid off the road trying to keep up with me. I felt no lack of traction at all. When we pulled him out, we saw why. His treads were caked with mud. It even extended beyond the outside of the tread by a half inch. My tires were not caked at all...

Compromises compromises...

Good luck!

 

[greentruck]

I'm real happy with our 255 KM2s. I'm a longtime BFG Radial MT user and the KM2 is a significant improvement over the old version. It's much more like an AT than the old MT.

As for road manners, it did feel a little more tippy than the stock Michelins. However, if you're driving style is prone to drifting through curves where the extra width of a 285 might a difference, you probably want a different vehicle than an 80 anyway

One advantage is that the weight and leverage of the 255 are less than the 285. In the long run, less wear and tear on the drivetrain and axles.

Another is fuel mileage. It takes less fuel to push the 255 down the road with its narrower profile, lesser weight.

Another factor to consider is tire pressure. I've not done a direct comparison between the 255 and 285 on this, but I do know that the 255's performance is very dependent on air pressure. Adding a little more PSI solved the initial tippy feeling. I haven't had a chance yet to do comprehensive trail testing (a peril of a too-long dissertation, I'm afraid) but with towing, adding a few pounds made a biog difference, so I suspect the low end of the range is equally adjustable. Think of PSI like a tool to adjust performance and you'll begin to appreciate the versatility of the 255.

 

[tromz]

Greentruck I always like reading your posts. I have been leaning toward 255s cause they are a little cheaper. Where did you buy em? I am a stickler on air pressure vs. conditions even driving around town
Thanks
Sherman nice pick thanks for the links.
Gfresh another reason to go MT I have a stereo to deal with noise!

 

[Gfresh]

FWIW, I just measured my stock LX alloys and the 255 KM2 last weekend: 75lbs...

 

[greentruck]

Greentruck I always like reading your posts. I have been leaning toward 255s cause they are a little cheaper. Where did you buy em? I am a stickler on air pressure vs. conditions even driving around town
Thanks
SNIP

tromz,
Mine came from Tire Rack. They have a warehouse close by in Indiana, near Chicago. Had them installed through a local outfit that has an ongoing arrangement with Tire Rack. Service and delivery were excellent -- they went straight to the shop, so I didn't even have to mess with them.

As far as noise is concerned, which a few have mentioned, well, it's a real off-road tire. Put Michelins back on if they're too loud...


They are quieter than the old MTs, so things could be worse. Unless you've stripped the carpet, etc out, the 80 keeps the noise out pretty well IMO. Even with the KM2s, it's still the quietest vehicle I've ever owned. If you have any real need for these, you're probably OK with what noise the KM2 makes.

 

[Black Rhino 13]

I've had my LC for about 18 months now. I've gone from stock to the usual mods in that time. I went from Michigan, to Colorado, to Montana, where I am now. And in that time I went from stock hwy tires, to 265 MT's from Treadwright (retreads), to the 255/85 KM2's. 31" to 32" to 33". It's our family's only vehicle as we're both students and we have two small girls. We live in Montana so there are plenty of opportunities to do various off road and backcountry trips, which we take year round. The Cruiser is a big part of our life and all four of us get our share of input on things. princess: really wants a snorkel)

That's the background and context. We love the KM2's in 255. Just love em. Except for one thing. Ice. They are quieter and smoother on the road than the wide flat tread we had on the Treadwrights. The KM2 has a pretty darn narrow contact patch when aired up and it's fairly curved, kinda convex seeming. Plus, the lugs are like small thick brownies with a fair amount of space in between them. They are amazingly quiet in my opinion given their design.

However, those solid pieces of rubber on that narrow curved tire means you don't hardly have any ice traction. I mean 360 degrees it's an issue. You have to be really careful on sheer ice. I've even found myself throwing it into reverse as I was about to roll (w/ABS) right through a stop sign into oncoming traffic. That only happened once and was part of my learning curve this winter. It did stop in time, but I had already shifted to reverse too. A little scary at first. And naturally they do sink a little more in snow than a wider tire would.

That can also be tricky. These tires dig. So, recently I very quickly dug and sunk about 10 inches or so and was stuck. Stuck w/ 3x locked. I looked around and I wasn't even touching the axles, high centered, or any of that. I figured it out pretty quick. The tires had turned the holes I was sitting in into icy upside down wheel wells. Again, no traction on ice with these tires. I was just spinning four tires in smooth icy holes. Was that easy to fix, absolutely. I was only stuck about 4-5 minutes. All I really had to do was shovel around each tire enough to get the smoothed out part gone and get a couple of inches of momentum going. Reversed right on out of there. The good news is I got further up that mountain road than anyone has yet in a wheeled vehicle. I just use this as an example of this one problem as it is something I've had to adapt to. However, I get great traction in and on snow. The flip side of the ice issue is that when we had 16 inches of snow here a month ago I could not get stuck and I pulled literally dozens of people out of the snow.

Having said that, I feel super secure on them because I "know" they are an amazingly well built tire. I got mine at Costco and I like to get them rotated and balanced pretty often just to be safe.

I don't think it fits well under the rear though. The 32" was fine, but I think the 33" rubs some. I've considered putting it on the roof rack till I can afford a rear bumper with tire swingout. Whatever that problem is, I think you'd have that with any 33" tire.

I do wish there was a 35" skinny KM2 but I'm happy with the 33's. They look just right with my deflared body and 2.5" lift. I'm so happy with these that I bought a $400 set of studded chains because I intend to replace these with the same tire some day.

The ice issue just means drive carefully or get some cables or something if you have ice a lot. I have even recently looked into tires again and I can't find anything that I would swap out these for.

Good luck!

 

[greentruck]

Hey BR13,
Yeah, that ice thing. Well, damn few and only very specialized tires work on ice anyway. Or just go for the chains, which may be a better solution for Montana. But...

With 25 years practice running radial MTs, ice driving on the KM2s is old hat for me. I just drive like I did with the MTs and I'm plenty safe -- well, at least a little safe

On ice, the KM2s are an improvement on the old MTs. The rubber compound seems to be softer, although it's still not what I'd call grippy.

Versus the 285s? I doubt there's actually much difference. You might feel safer, but I'd bet you can swap ends just about as quick.

 

[tromz]

Cool thanks Black Rhino..There is a Costco that my dad is a member Ice and winter driving can be an issue here in Virginia and I like to ski so all that info is helpful
Green truck is right nothing works well on ice.

 

[Black Rhino 13]

Hey GT,

I was just surprised how slippery they were compared to my previous tires or any previous tires on any vehicle. I agree with the rest. If Tromz is going from Revo 275s to KM2 255's, he might benefit from my hopefully well detailed descriptions. But, 255 vs. 285 KM2's, yeah, I see no reason for the 285s. According to Tire rack the 285 is 1 inch wider except at the tread, which is 2" wider. Just seems like higher rolling resistance and higher noise to me. And on Tire Rack the 285s are $56 more EACH! That's a free 6th 255 with change to spare if you count shipping even!

 

[Black Rhino 13]

Cool thanks Black Rhino..There is a Costco that my dad is a member Ice and winter driving can be an issue here in Virginia and I like to ski so all that info is helpful
Green truck is right nothing works well on ice.

No prob, Tromz. If the Costco price is as different as the Tire Rack price, just put your savings into some chains. I have lots of info on that too.

With all I said, I still love them and wouldn't take anything else at this point.

In Missoula, Costco is the only place that puts nitrogen in the tires. I think it's nice for keeping the tire air pressure more consistent.

 

[tromz]

Black rhino When its icy try dropping some air pressure . Careful though cause the rubber isn't gonna warm up like a normal day.

 

[Black Rhino 13]

Black rhino When its icy try dropping some air pressure . Careful though cause the rubber isn't gonna warm up like a normal day.

Yeah, good idea for traction. I've not yet messed with tire pressure changes in my wheeling / driving because of the terrain here. Mostly roads. Very few bouldery trails and stuff like that. I'm reluctant to fiddle with the air since my tires are filled with Nitrogen. I mean, I know it's probably fine to mix regular air with nitrogen, but I assume I then lose some of the benefits I had with the all nitrogen tire fill. Aired down or not, I guess you have to make adjustments to your situation.

It's really a narrow range of ice and packed snow plus +/- 32* where I've had to adjust. Here in the banana belt of Montana we get daytime temps right around or just over 32 most of the time in the winter. So, we only have the issue briefly, right after a substantial snow when cars are packing it down or it's melting and freezing day and night.

Like Greentruck said, the rubber compound is pretty good. It's just the lack of any siping and reduced footprint that affects traction the way you would expect it to. I think the important thing is predictability, and I do find these tires to be nice and predictable. I guess that's a lot of what we like about them. Even their cons are comfortably predictable and you can easily adapt to them while enjoying all the pros.

I just got my OBDII cable in yesterday and went for a short drive on the interstate at 75 mph with a friend. I had hooked my laptop up to the LC and my friend was telling me stats. I was focused on the info, but I just can't remember it being intrusively noisy for normal talking at 75 mph with bumper, roof rack, etc... I think they're really quiet tires, though I haven't had hwy tires in a while now. Maybe I'm used to it? Maybe some day 'Mudders will be so anal that they'll start measuring decibels in their vehicles?