I have a 99 f150 4wd with a 4.2 standard shift that i just bought last week. the previous owner had put 265/75/16 tires on it. I seen on the door sticker that it originally came out with 255/70/16 on it. Now my question, This truck is very weeeaaak and gets poor gas mileage "12" anywhere you go, is this due to the tire size change or is all the 4.2 engines like that. Any comments will be helpful

thank you

coonhunter

 

Anything you can do to reduce the load on that lil engine will help. Everyone wants the 'look' of big tires but 95% do not realize how much they lose when they go up in tire size. If you want big tires then you better have a big motor and big gears.

 

My roommate's F150 2wd has the 4.2L in it and he already get crummy mileage.

In your case, larger tires definitely wont help, and another thing to consider is did he re-calibrate the speedo when he put the larger tires on? You might want to check that as well, if he didnt recalibrate then it would appear you are getting less miles than you really are.

 

The 265's are only about 2 inches taller than the OEM tires, which is not a big jump. I'd start shopping for lower gears rather than go to a smaller tire.