When I first started seeing news of these I was really excited. Then I saw one (for real) and sat in it at the fair for Earth Day around this time last year. It was neat, but every time I asked the Elio team showing it, questions about why they didn't do things differently to further increase its efficiency, they would completely dismiss it and change the subject. In the end, I wasn't overly impressed.
Best Tank = 42.72 mpg
Mudflap Delete, Fully Synthetic Oil, Max Sidewall PSI, Warm Air Intake, EOC Kill Switch, MPGuino, Lowered 1", Vacuum Gauge.