Every now and then I hear someone say something about whether the top gear in an MCS is an "overdrive" ratio or not. Does this term mean anything in the context of a FWD car with a transaxle?

Back in the days of RWD cars, an overdrive gear was one where the RPMs coming out of the gear box were lower than the engine RPMs going in. Thus, you could have, say, a 4.11:1 rear-end for quick take-offs, and still get decent highway cruising.

How does this work in a transaxle? Does the MINI have a separate gearbox, that feeds into another set of final drive gears?

(I haven't been "into cars" since about 1975. My second-adolescence is currently waiting on the docks at Southampton!)

 

Overdrive is simply a gear (or gears) that is less than a 1:1 ratio with the engine RPM, so for every revolution of the engine, the output of the transmission will be more than one revolution.