OK, so the tire I'm looking at (Nokian Vatiiva) doesn't have an LT tire in the larger tires, the stock size is E rated and heavier than the other sizes I'm considering. I'm leaning toward the 235/75/16 for the extra clearance and a width compromise. Most of my driving is my 80 miles of commuting, but I will be using the Jeep to fish (mostly beach) and hunt. Is the P rated tire going to hold up to weekend off-roading. Will the E rated tire ride rough on the road? Which will affect mpg more, a heavier/narrow tire, or a taller/wider tire? What if I want a 1-1/2" CRD lift later (Daystar KJ09123BK), tread depth, speed rating, what about rubbing....... Over thinking this, not me!


Size Load Weight Diameter Width Tread depth Speed rating
LT225/75/R16 E rated 40.6 lb. 29.5" 8.8" 17/32" Q
235/75/R16 P rated 33.0 lb. 29.8" 9.3" 14/32" S
245/70/R16 P rated 35.0 lb. 29.5" 9.8" 14/32" S

Unsprung weight, particularly tires/wheeles/brakes, may effect your jeep's performance or mileage more than any where else. I've heard that a 1 pound gain there is like a 10 pound gain in sprung weight. So, a weight increase is going to show up at the pump, especially on a commuter.

However, the weight numbers you are posting really are not huge differences. And the width changes aren't huge, either.

When you add a lift, these things change more. Your overall wind resistance is increased, and it exposes more tire even if the tire is of the same size. A lift will probably be a bigger wind factor than the difference in any of the 3 tires you listed.

An E-rated tire is generally going to have a stiffer sidewall. Although it is a touch porky, the KJ isn't really all that heavy so compressing the sidewall to soften the ride may be an issue. An E-rated will be more puncture resistant off-road, though.

I actually noticed a difference in the ride of my '79 when going from 31x10.5x15's to the e-rated 285/75/r16's I am using now. And it rode like crap to begin with. I think that the load rating increase was the biggest factor in that.

I personally would stick with a s-speed rated tire near to stock size if almost all of my driving was highway speeds. If it was more surface roads, I'd take the chance on the e-load rated tires.

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'05 KJ 3.7L/6spd/241 245/75/16 MT's
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