parker.rowe wrote:
I'm not sure why people think the rear gear ratio only changes rpm/mph.
It increases torque multiplication to the rear wheels. It will tow more easily in all gears. It may allow towing one gear higher than usual
If the truck is in fact a 3.73 truck, it will make a difference going to 4.30's. Ford didn't offer that option for fun.
Yes, it will increase cruise RPM in 6th by 2-300 rpm. Might loose 1mpg unloaded. But as Fish stated you may gain mpg towing.
You know WHY it "tow more easily in all gears?"
Because the engine is running at a higher RPM at all speeds!
The engine produces more HP at higher RPMs, up to the peak of the power curve.
People think "gear ratio only changes rpm/mph" because that is precisely what it does.
If you were doing 60MPH at 2000RPM with stock 3.73 gears, you will need to rev the engine to 2305RPM to maintain 60MPH with 4.30 gears, or you will only be doing 52MPH at 2000RPM.