Re: What RPM at 60 mph for best gas milage?
Well, frank is most right of them all hehehe, but on a serious note, i think it depends on a vechicle and its hp. for example the new TAs and Z28s run something like 1200 rpm @ 70 if im not mestaking. those things get 29 on a gallon on highways and supposed to have 308 or 315 hp stock and 320 torque. (6 speed, got to love'em). The sixth gear is supposed to be for fuel efficiency period. My guess would be right around 1500 rpms for a truck should be fine especially that the torque is the same in both. Unless your towing. But then again im no pro. (right now, all stock, my 94 has 2000rpm @ 70)
Will work for mods
Current mods--> 31x10.5x15 ProComp MT, 15x8 AR767 rims, K&N, MSD Ignition Coil.