ok i have a 93 f150 5.0 auto 4x4 31x10.50 tires with 3.55 gears. right now i get 22mpg on the freeway at 65mph and 13mpg around town from 25-55mph. i just want to know what kinds of fuel mileage difference i'm looking at when i go with 4.10's.

 

probably 15 mpg in town and 22-23mpg on the highway

plus your excelleration will be faster

 

i'll seriously get better on the highway? shoot i'll probably get them soon then. i'll see how much quicker my truck can get the speedo up to 90mph with them when i get'em. thanks.

 

Pretty safe bet that your in-town mileage will go up, but I'd suspect that the highway mileage will stay about the same or possibly drop a bit.

I'm assuming you're keeping the same size tire with the gear swap?
If you're going with larger tires, expect the heavier tire to take a bit more power to turn...which will pretty much balance out the increase you'd get from the gear swap making the drivetrain easier to turn.

 

yeah i'm keeping the same size tire. but its good to know that it wont hurt fuel mileage much at all for the highway. thanks for the replies. thats all i needed to know.