I have a 2000 F150 4x4 ext. cab. I get about 15mpg on average with 265 Uniroyals. I have the K&N FIPK and flowmaster dual exhaust. If i put 305/70/17 Maxxis Bighorns on my stock wheels how much decrease is fuel milage can i expect?? The tires will fit those wheels safely right?

 

You will need to crank your t-bars before you put those on to level out the truck and allow for better fitment, I assume you have stock rims....I got around 13-14 avg. on my old 2000 with 285/70R17's. I had flowmaster dual exhaust and a K&N drop in...

 

I cranked them up when i first bought the truck to level it out. And the stock tires have always looked tiny ever since. So maybe 12-13 then with 305s. 14 If i'm lucky and drive like an old geezer? Yea stock chrome wheels.

 

yeah it will look much better! the looks will more than make up for the 20-30 miles every tank you are giving up.

 

I agree with Hawg Man, the look's will be worth a little less mileage.