I have a 4x4 Supercrew XLT with the stock 255/70/17's and 3.55 LS gears. I am about to buy some new AT tires and have been juggling the decision b/t 265/70/17's and 285/70/17's. Changing the gears to 3.73 LS at this point is not an option. Will I notice any performance or gas mileage difference b/t the two? Why would I choose one over the other? I don't neccessarily want to "lift" the truck with big tires, but I also don't want to stand back and think that the tires are two small for the fender openings (as is currently the case). Thanks for all of your help and input.

 

265/70 vs. 255/70 will hardly be 1/2" larger. Probably won't even notice the size differnce. 285/70 you would notice the look more vs. stock.

As for performance, most people don't notice 33" tires on F-150. I do, but I tend to drive more agressively than average. Acceleration and braking more significantly, especially while towing.

 

I went from 255/70-16's to 285/75-16's and didn't notice a difference in performance. However, my speedometer is off 5mph at 60mph.

 

What about the 3.55 gear ratio? Should this even be a factor in my decision process?

 

I have 3.55's also.

 

I have 35"s on mine w/the 3.55 and while I DID notice a difference, it's not bad at all. I'll probably eventually go w/4.10 or 4.56 but it's not a priority right now because the difference is easy to live with. I know I'll get better mileage and my engine & transmission won't be suffering as much w/the gearing back into the power range but again, it's not a severe difference. I don't think you'll have any issues except the speedometer/odometer. I have a Superchips programmer so that's not an issue for my truck.

 

i would go with the 285/70/17 because you are going to have less noticble space in you fenders. And No you want have to re-gear a buddy of mine turns 35's over with the same gears.I just wouldn't be as hard on the truck.