I was told that 285 will increace your fuel milage over 265 cuz of the low geared tranny?. is this true and what fuel milage are you getting w/285. I want to buy 285. Thanks cody

Not true unless your driving is all highway, and the tires are as aerodynamic as the 265's, and weigh the same.

Bigger tires almost always means lower mileage.......Unless ^

I saw a 1 mpg. decrease. (17.5 hwy. on 265's and 16.5 hwy. on 285's) ....harder on your brakes too!! My 285's are coming off.....4-sale. Good luck, Ed.

I sure lost 1.5 to 2 miles per gal with my 265. Like the tires but sure miss the miliage. Will probabley go back to original with next set.

throw a power box on and just the opposite, from my own testing i seen a 1.5 mpg better mileage, with the 285 over stock tires, only makes sense, cause you are close to 400 rpm lower, and i mostly due hi way miles, now if you were running a stock hp, things would be different, i feel stock has not enough tq to handle the 285 requirments for best economy, now when i am running 73mph, i am still under 2000rpm, using tq rather than hp

I saw a 2 to 3 mpg decrease when I put 285's on, but the improvement in appearance is well worth it. Speedo is off about 7% also.

Interesting to hear all this. Bigger tires means must have MORE POWER! Hoh hoh hoh (in manly grunting voice)

Question...

I know the speedo is incorrect with oversized tires, but what about the odometer/tripometer? I was under the impression that this would also be affected. If so, are you guys with 1-2 mpg decreases taking this into account? This would probably affect it by about 1-2 mpg. I personally don't care about 1-2 mpg, I hate the factory dounuts:D

Ryan, exactly! My mileage was hurt, but so was my average speed. Get it? If the speedo is off, the odometer is also likely off, which means your mileage will be less (unless it's corrected via Predator or similar....)

Ryan, yes when i figure out my mpg I add 7% to the whatever the speedometer says and then calculate my mileage. I really did see a 2 to 3 mpg decrease when I switched to 285's.

When I had the stock 245's on, my mileage was 16 town/18 highway. With the Michelin 265's, corrected mileage is now 14.5 town and 16.5 highway. Tires are great though and wouldn't go back to stock.

big tires early in the life of the truck means longer warranty !!!! i put 315s on at 10K and am now at 35+K, er, I mean 33K !!