I realize the size difference
I realize the fitting difference lifts cutting etc.

What I don't know about is the gearing and axle strength.

I ran 285/75/16 on my last 4runner I understood the gearing difference and speed difference.

But how would a discovery do? They both have the same horse power even though the disco is a v8, I feel the discovery is geared lower.

How bad would the acceleration be with the 255's?

Axel Strength:

I never understood this one, how do the axles fail? Whats the weak spot? I never understood how a larger tire could kill a SOLID axle..

Should I worry about the axle with 255's?

Most of my wheeling is done sadly in mud, [its all we have] where the taller tire really helps [so does wider but I want to keep skinny] so Im not going to be exposed to ANY rocks, though there are times where I will be flexing.

 

You'll notice a difference in power when going up hills(on the highway) with the 255s. Off-road I've never had a problem with axle strength, you just have to be easy on the skinny pedal. The extra clearance is nice with the 255s....
The larger the diameter of the tire the more leverage you're creating on the axle, usually at the differential. Imagine using a small wrench trying to get something loose, then you add a breaker bar and it comes loose with little to no effort. It's the same affect with your axles and taller tires.
I have pics with both 235s and 255s...

 

thanks for the post!

So, in the way your describing it, it would only seem to be an issue when the tire begins to lift off the ground, in which the axle will be supporting the weight of the tire. But I don't see how the weight of the tire could be any worse than what it normally handles, the weight of the vehicle.

Also can you describe the pictures you posted? Which pictures show which tires?

 

is it rotational weight that destroys the axle?

edit: by leverage you meant in the direction of the tire, i was thinking axle

 

The pic on the left is with the 235s and the one pic on the right is with the 255s (my truck is the one in front).
With one wheel in the air you'll be fine, as long as you take it slow. If your tire is in the air, you're spinning your tires, and you come slamming down on that tire, that force from spinning wheel to sudden stop can break you axle or diff.

 

The biggest breaking point is the spider gears in the carrier. Trust me ive broken plenty. But if your gonna put lockers in thatll cure the problem.

 

Sorry to hijack guys....

Esteban - where did you get that rack that you have in the rear of your truck? Or did you fab it up yourself? And BTW, your truck is wicked awesome!

P.S. - can you teach me to play the guitar?

 

If you are wheeling in mud, the skinnier tire will work better. Growing up in wet cow pastures taught me that. You will be able to get down to solid surface with skinnier tires instead of slopping around on top of the muck. When the big, wide tire fad came in, I had to pull many a person out of the cow poop.

The taller the tire, the more strain is put on the axle to spin it. Your main problem will be creeping in low. But, as already stated, the diffs are the weaker point, so upgrading to lockers will take care of you. Then you are looking at axle strength, and if you are spending the $$ for lockers, upgrading the axle shafts shouldn't be that big of a deal.

If you are worried about not having the fanny to get up and go on the highway, swap the gears in your diffs. I think Mike is running 4:11's to compensate for the taller tire.