Can car companies use turbos and superchargers with smaller engines to make the same power with better mileage

Question

Can car companies use turbos and superchargers with smaller engines to make the same power with better mileage

Answer 1

the heat generated by the gadgets could also pose some problems for long travel, but no problem for short distances.

Answer 2

Same power, yes.  Better mileage, no.  A turbocharger is simply a way of increasing the effective displacement of an engine, and are not really justified for automotive use, as the increased weight of a bigger engine is not a serious problem.  But for piston-powered airplanes, where weight is crucial, turbochargers are useful.

Answer 3

No efficiency is ruled by energy in divided by energy out.

Race cars use more fuel than my Grand Mother's car.