4 cylinder has better gas mileage, but obviously doesnt have the power. if you are going for affordability, would you go with a mazda 3/6 with a 4 or 6 cylinder engine. We are talking about 20/27 mpg with a V6 mazda 6 and 25/32mpg in a 4cylinder mazda 6. 28/35 is the mpg for a mazda 3 with a 4 cylinder (they dont make v6's that i'm aware of)