OK, so real quick. I have the 1.4 liter turbo. I am happy with the acceleration and the fun to drive aspect, being that I have a 6 spd. If you are just looking at gas mileage. Do the calculation per mile. In New Jersey, where I live diesel 3.09/gal. Calculate out 46 MPG and it really is a wash. It is 6.6 cents per gallon versus my 7 cents per gallon @ $ 2.45 per gallon @ 35 MPG. (1.4 lit turbo). So I guess it comes down to torque? Are you getting from 0-60 faster? IDK about that... I could be missing something, but your #1 advantage you listed was MPG, and I don't see a net advantage there price-wise. What am I missing?