In my estimation the test of an engine is its fuel efficiency, the fuel burned for each horsepower produced, crunched some numbers and a Lycoming O-720 at 75% best economy comes out at 34.44%, R-3350 at the same setting 35.71%. Pretty good I'd say, without hanging electricity dependent bits off of it. Haven't been able to find car figures to compare, I've read that all the do dad electronics on todays average car has more to do with meeting pollution requirements than improving economy