Change Differential Gears to new Ratio?

smkettner wrote:

pianotuna wrote:
Then how come I use less throttle at 50 mph than at 60 mph? (and way less fuel)

Jagtech wrote:
Lower engine speed equals larger throttle opening, which effectively negates any fuel savings.

I believe we are talking same speed less RPM.

Yes, same road speed, less engine rpm, due to higher ratio gearing (numerically lower), while the engine is also under load.

It is proven that operating at low rpm with foot deep into the pedal produces lower fuel economy, than operating at higher rpm with less thottle, when the engine is under load.