Ha Ha, my DD is an 05 Civic hybrid and all I did the first year was watch the MPG gauge and try to get as good a gas mileage as I could. I even intentionally tailgated semi and drove 55 or below on the freeways. With that, I was able to consistently reach 47+ MPG average over a full tank. It's called "miling" in hybrid circles.
Compare the Z to that, what's the point? Enjoy the power and speed; forget the MPG.
Of course, my problem now is I try to drive the hybrid like the Z in my daily commute and it just won't go as fast for some reason.