A question for 5.4L F150s' with 3.55's. What is your RPM at 70mph?
#1
#2
I'm not sure of a calculator as such, but if you're planning on going by your tach, it's not gonna be that accurate anyways...... I'll bet there is a mathmatical way to figure it, but I have no clue on that either.
Just to give you a ball park figure on what MY rig does, I am showing 1900 rpms at 70 mph. I have swapped out the VSS gear for one to compensate for my slightly taller tires, and by drivng past miles posts and counting, I'm pretty darn close on actual mileage.
My tires are 265/75/16 (~31" tall) and am running the 3.55 gears and a E4OD tranny.
Just to give you a ball park figure on what MY rig does, I am showing 1900 rpms at 70 mph. I have swapped out the VSS gear for one to compensate for my slightly taller tires, and by drivng past miles posts and counting, I'm pretty darn close on actual mileage.
My tires are 265/75/16 (~31" tall) and am running the 3.55 gears and a E4OD tranny.