i have a 97 f150 4.6L. 98,000 miles k&n intake jet performance chip and a flowmaster with 3.55 posi gears and 235/70/16 tires and getting about 12-13 ish mpg. i can make a little over 300 miles per tank. my buddy has a stock 5.4L. with 265/70/17 tires and a 3.55 posi im not sure exlacty but he can get a lot more miles per tank then i can. i was wondeing if i put 265/75/16 tires it would help the gas mileage?

 

I have a 1997 f-150 with the 4.2 and i just recently had 265/75/16 and i was getting about 13-14mpg with them I believe i have 3:55 also not exactly sure but i switched to 285/70/17 now im getting about 11-12..I have my old rims and tires forsale for 400$ for everything if you are interested i can send some pictures

 

bigger tires wont help gas. period. however that jet chip is probebly one of the problems your gas is so bad. are you running the right octane with it?

 

im just running 87

 

is it stage 1 or 2?

 

i looked up your chip and it says you can use 87 octane but it was designed for 89-93. this may be attributing to the crappy milage. since the chip advances the timing i would go ahead and start using atleast midgrade. have you had any knocking with that chip? if so this should fix it

 

thanks man. do you think i could just buy some octane booster and not actually spend $3.50 a gallon or whatever it is

 

no octane booster

 

I've got a 00 4x4 f150 and it has never got better than 14 mpg since it was new. That's with a superchip and dual exhaust, k&n filter. Fact is that fords and gas mileage do not go together.

 

It all has to do with how heavy your right foot is

 

Driving habits are the most significant impact on fuel usage. Comparing yourself to any friend or anyone on the internet is a waste. I've never gotten more than 14.5mpg in 50 miles in my current F-150.

Spend $5/tank on octane booster or $2 for mid-grade fuel? That doesn't make financial sense, even it did work (which it doesn't).

Remove the chip and Blowmaster to increase fuel economy maybe by 15% if you are unwilling to change driving habits as most people are.