This would be for my Fiat 500. It gets very good mpg out of the box. With a manual trans. and driving skill you can get well over 40 mpg without trying too hard. So I am looking for motivation to perform mods (which would be better handling).
FYI, The so-called "multi-air" engine in the 500 is unusual in that it has no throttle. The intake valves are controlled hydraulically (by oil) in a continuous fashion. At 1.4 liters displacement, it is the biggest engine they have designed for the car. In Europe, they also have a 1.2L, and 1.3L diesel (sob!)
But I like that the little four-banger dozes in slow traffic (leans itself down) and still gets good mpg.