I have some Bridgestone 235/75-15's on my 2003 Tracker. With the body lift going on this weekend (plus the OME suspension lift already in place) I have decided to go with 31-10.5-15 BFG's.

Last night I was reading warnings about people changing their LT tires on their picup trucks to Passenger car tires, because its cheqper. I read and understand the danger of downgrading a heavy vehicle to a light duty tire. I don't believe there is any danger in upgrading from a Passenger car tire to a LT Light Truck tire. Heavier, stronger, higher load ratings, and all that jazz.

But what does it feel like. The 31's are 10 pounds heavier than the 235's. That can't be good. Anyone have experience making the switch?

The LT's will be a little heavier and stiffer (more plys in tread and sidewalls). But nothing that will ride uncomfortable on your Tracker. If you off road at all I would reccomend a minimum of an LT tire to keep form puncturing it off road.

Zig

Double what Zig said.  You only loose 3 or 4 sidewalls before you get really tired of it happening. 

Fair enough. I understand the additional strength off road. But what I hadn't thought about was on-road. How does it change the on-road handling. Louder...sure. No big deal. What else?

Fair enough. I understand the additional strength off road. But what I hadn't thought about was on-road. How does it change the on-road handling. Louder...sure. No big deal. What else?

you get a sort of loose feeling due to the sidewall not flexing enough..... noise depends on the tread style.....no big deal.

i rode on passanger tires from when i bought the truck till a sidewall went on one and after a 6 month storage blew another on the highway (ya... not fun at all... tire didnt even go flat, tread just came off in a giant strip. wish i kept the tread strip for the memories...)

went from the highway straight to the tire shop for some upgraded tires, went from 205/70r15 m+s passanger tires to some 235/75r15 LT's (all terrains) made the truck look alot meaner and they drove like a dream.

speedo get right on after the swap (gps confirmed) no difference i could tell in the ride other then a bit slower accel in 3-4 gears (1-2 about the same, still lifts a tire in hard accel in tighter corner from stop)

I just went form the standard 205's to  LT 235/75/15 All terrains.  I'll second the loose feeling, it was weird at first, but you get use to it, otherwise I didn't notice much of a difference in terms of handling, noise, or power.

OK, I'm wondering what you guys mean by the vehicle feeling loose. 

Are we talking about tight and loose as in understeer and oversteer? If the sidewalls are really stiff, and don't flex as much, does this make the vehicle oversteer?

OK, I'm wondering what you guys mean by the vehicle feeling loose. 

Are we talking about tight and loose as in understeer and oversteer? If the sidewalls are really stiff, and don't flex as much, does this make the vehicle oversteer?

if you have ever driven a rig with mud terrains it is a similar feeling, not so much over/under steer but a sort of swaying at higher speeds nothing major, also depends on your tire style, with an AT you should be fine, not much of a difference than a normal AT

 To a point, it feels like when you run your tires a little low on air. It has nothing to do with an over or under steer kind of issue. just more of a mile wiggle. And I don't think it really has anything to do with the ply rating so much as going to a larger tire with more tread depth and taller sidewalls and a wider/larger footprint on the road. If you were to go from a 4 ply(Passenger) to a 6 ply(LT) of the same tire, you would notice the 6 ply is a little stiffer. Going from a 235/75-15 to a 31x10.50-15 and both are LTs, you would still notice a huge difference in ride and handling.