tire and gearing question..

[RttH]

I am going crazy researching tires. Here is what I have:
2000 Mitsubishi Montero, OME shocks. I am running 32 x 11.5 x 15 BFG AT.
I want to go up in size. I have 16 x 8 rims to switch to. I am seriously looking at 255/85 16 tires which leaves me with BFG MT KM2, or Cooper and a few others. I live and wheel in Colo. and Utah, and it is my daily driver.

Since I have the BFG AT to run in the winter now I thought about getting something like the KM2's for summer and offroading. It would be silly to put on BFG AT again (I think?).

Question 1: AT or MT? I had BFG MT in the past, they were fine on road but not great (mostly noisy. New ones are supposed to be better?).

Question 2: 255/85 16 or 285/75 16? How much will my truck feel the difference? I have no difficulty with 32x11.5x15 offroad.

Thanks in advance!
Roger (see you at the Expo!).

 

[akfj40]

question #1 personally, im not a fan of the bfg mud's their A/T's diff story.
I would do Toyo opencountry M/T's i love mine yes they are pricey but last a ling time and wear good also they are quite and you can still do some decent wheeling.

question #2 your first tire is roughly 33.1" and your second is only 32.8" not much diff to where you would fell it. I would go the 285's and go from there.

http://www.4lo.com/calc/gearmetric.htm

 

[Dan Lee]

I would say go with the 285s. Much more common of a tire. I see BFG ATs in that size on Craigslist all the time.

 

[Pskhaat]

Why not 33x10.50r15s? Just my opinion but I prefer an MT in snow over an AT.

 

[RttH]

Thanks for the input. The reason I went to 16" wheels was I was able to get them real cheap ($50 for 5 from another Montero) and I was told that tires on 16" wheels were rated better due to stronger sidewall, etc... is this true?? I am considering 255/85 (33.5 x 10) because I am finding them a little lighter (better gas mileage, easier on truck), and taller than 33x10x15 (32.5 x 10).

But you now have me reconsidering the 15" again. I appreciate all opinions!
Thanks!

 

[RttH]

I think I am getting somewhere...

Going from 32 x 11.5 x 15 to a 33" tire (using BFG's chart) I gain +1" height and lose -1" width. Thats ok.

Going to a 255/85 16 I gain +2" height and lose -1" width but add 7lbs/tire.

A 285/75 16 gives me +1" height from my 32's but adds 13lbs /tire.

So what are the advantages of 16's over 15's ?? strength? or not much?

I appreciate this forums input! Makes decisions easier!

 

[Pskhaat]

I wouldn't say you should be necessarily considering a 16" wheel or tire combo any stronger/better than the other. A lot of 16" wheels (and 17 & 18) to accommodate larger and better brakes. The sidewall of the tire is simply how it is manufactured, not necessarily due to the inner diameter for the wheel. Is a 16x8" going to be too wide a wheel for a 255? some think so some are okay. I think you may have more total options and value in a 15" wheel, but appreciate someone who goes OEM on the 16s For any given tire total diameter a 16 wheel will have less an aspect ratio. I'm considering a 15" stock wheel for my Troopy and shod it with 33x9.50r15s.

 

[tdesanto]

Roger,

I have the gen III Montero, so it's different; however, I have the 285/75 BFG ATs. They're a tad too wide for this truck in the front. Not by much, but I had to trim just a slight bit to keep them from rubbing when fully stuffed and turned all the way.

When I have to buy new tires, I'm seriously considering the 255/85 to get a skinnier tire in there. I think you might be well served by this size as well, or a skinnier tire on the 15 inch rims. Since you already have the 16" rims, why not go with a 16" tire and then you'd have both sets to swap whenever you want?

As for feeling the difference (I'm assuming this is the gearing part of the question): stock on my truck is 265/70/16 (31") and I went to the 33" tire. Without towing, I didn't notice it too much, unless climbing hills, but the truck could handle it. Stock diff ratio on mine is 4.3:1. For towing, it just couldn't handle it. After swapping to 4.9:1 gears, the 5-speed auto is right back at home with the 33" tires.

 

[RttH]

Thank you very much! (everyone).
The reason I bought the 16's was to get that extra height but started to worry about weight, gear ratios, etc... Since I have the 32's (really 31.7") BFG AT on 15's I thought about keeping them as my winter tires (someday when they are too worn putting real winter tires on the 15's) and using the
16" wheels as my summer/offroading tire and maybe put MT's in a 255/85
(33.7") The 285/75 is not much of a change from my 32's and the extra unsprung weight seems too much.

Wife is not too excited about a set of wheels/tires in the garage or the expense of another set of tires either...so I could go the 33x10.5 15 route.

Another quick question...when one refers to swapping to a different gear ratio, is that done in the transmission or axle?

And another....Has anyone driven the new BFG MT KM2 on highways much to give an opinion on how they ride?

Thats it for now! Thanks again!

 

[tdesanto]

Another quick question...when one refers to swapping to a different gear ratio, is that done in the transmission or axle?

In the axle. Actually, you're replacing the ring and pinion gears inside the differential.

 

[chuck45]

Another quick question...when one refers to swapping to a different gear ratio, is that done in the transmission or axle?

And another....Has anyone driven the new BFG MT KM2 on highways much to give an opinion on how they ride?

Thats it for now! Thanks again!

Gears are changed in the axles.

I've got a set of 35" KM2's on my JK 4dr. They ride great on the highway as long as you use an appropriate air pressure and not anywhere near the sidewall max. I run mine at 28 psi.

 

[RttH]

Thank you. I am getting closer to a decision...and I am leaning towards the km2's in 255/85. I plan on keeping the BFG AT's on 15" rims for winter and maybe longer trips. I know my truck will be fine on highway with taller tires, its climbing at 9000+ feet offroad in rocky terrain that I worry about gearing issues. I may be ok. I never had any problems with the 32's, but the 255's will weigh more too.

Thanks for everyones input!