Yes, lowering it would be a good idea for improved aerodynamics and reduced drag, thus at least a MINISCULE improvement in MPG, if no other factors contribute the other way.

By the way: I entered the contest to WIN that Maroon 5 HCH, so the rest of you can save your time by not entering - I've got it locked up !! I'll let you know about the MPG when I get the car....