[MetroMPG]

Best return on investment is to adjust the nut behind the wheel.

Have you studied the 100+ hypermiling tips (linked at the top of the page) to see which ones apply to your driving regimen/environment?

Sorting out a fuel economy display that does instant & resettable trip avg is a must. You can't manage what you don't measure, and going tank by tank isn't fast enough feedback.

After that... the saran wrap aero cap sounds like fun!

Welcome to the forum.