If anyone is looking to improve their MPG's beyond just HHO, check out these modifications that you can do to your car: http://ecomodder.com/forum/fuel-econ...ifications.php

The easiest and most effective are:
-smooth wheel covers
-rear wheel skirts
-grille block
-kammback

combined, these could improve your fuel efficiency by 15% depending on your vehicle.

I hope you find these ideas useful!

Thank you,
Jim