redcelica

Just bought a 2012 F150 (front leveled) yesterday with the 3.5L and got 14.7mpg highway with cruise on going home. Safe to say, I'm blaming the 35" BFG A/Ts. Wondering if going with something more stock size and a on-road use tire will net me a lot better MPG. 17+ would be worth the investment to me.

Didn't buy the truck for looks or "compensation," so I don't mind going back to a 275/55/20 or so

http://www.tirerack.com/tires/tires....LX20&tab=Sizes

I use the truck for short trips to lowe's, hauling, and towing. Light snow use (I live in NC) w/ 4 wheel drive. I think a smaller tire will help with applied torque when towing as well. I'll be towing about 5000 lbs...so those should be okay for the max load rating.

130428

the lighter / less aggressive tire will likely make a difference. a 2.3 mpg difference, that no one can tell for sure...

before anyone else mentions it, have you checked your speedo / mileage to see if it's accurate (= accurate mpg reading), or did you hand-calculate? That could (or not) mean that you are getting slightly better than you think.

redcelica

Just filled up the tank for the first time, so I'll calculate on next fill up. So the MPG calculation done by the computer is in fact dependent on the tire revs per mile that some sensor is detecting?

Jeriko

exactly. if the computer isn't calibrated for the size of tire (specifically, rotations per mile), it will record that you're not going as far as you actually are going if it's still programmed for stock. So less distance recorded and same fuel used will result in higher apparent consumption.