I have been looking at the Fiat 500 TwinAir website and reading about its 2 cylinder turbocharged engine. Apparently it pumps out 85bhp and manages 68mpg (or 56mpg if you count like an American). This rivals some diesels and isn't far off hybrid performance either. I'm now not sure if it's worth paying extra money for the black stuff or for those premium batteries that are relatively unproven. This got me to thinking, how many cylinders do we actually need in our cars and what overall capacity do we need these days? Personally I drive a car with a 3 cylinder, 698cc engine. It too is turbocharged and I find that it is more than capable of handling every type of driving that I want to do. This includes the fabled "on ramp" where I believe some people think that only 8 cylinders will do. What is the smallest engine that you would consider having in your next car?