Gearing Question

I have a gearing ratio question. Will one of the following differential/wheel size combinations transmit more power and/or torque to the ground than the other?

The application is a hill climb for a Model A Ford. One combination would be a 4.11 differential with 21" wheels (approx 30 3/4" tire diameter). The other combination is a 3.70 differential with 16" wheels (approx 28" tire diameter). When I do the math, both combinations will yield about 50 mph at 2000 rpm (within 30 rpm) in 3rd gear (1:1), so for the sake of this discussion, I will consider both combinations equal in effective final drive.

***uming that both wheel/tire combinations weigh the same, the rolling resistance is the same, the car will be doing most of the actual climbing in 3rd gear, and the engine will not run out of rpms, will one setup get the car up the hill faster that the other?

I'm thinking there may be something to this, but don't know for sure if there is a difference in performance.
As always, Thank you in advance for any insights.
Peace

 

It seems to me if the math you refer to is correct (I didn't run the numbers myself) and the speed @ rpm is about the same..........neither would have an advantage over the other.......except for maybe tire traction yielded by one over the other.

I may be missing something here, but if so, I obviously don't know what.

Ray