This is on my 99 F150 4x4 with tow package and off road package 5.4 and i believe 373 non ls gears.

Came with 17 rims stock.


I just put 16 rims with 255 70 1617 tires, will that cause any drivetrain issues?
Will it throw off the shift points?
Besides mileage going up faster and speedo being off by 5.

I should see better gas mileage with them vs 315 70 171617 .


Thanks

 

If it were my truck and I didn't have a programmer to change the tire size I would go to the dealer and have them change it.

My buddy just added larger tires to his 2011 and he went straight to the dealer. IMO it is money well spent whenever you change tire size away from stock.