I drive my '02 Z06 about 2 out of every 3 weeks, and dirve the '87 Turbo Regal the remaining week. I drive 25 miles each way, and try and work only 3 to 4 days a week. The Z06 gets 18.9 mpg on the average, and the Turbo Regal gets 17.5 average. Unfortunately, the Honda CBR1100XX is buried behind the other 2 so I can't get it out and shoe it to work every 3rd week like I should.