I made Hydrogen fuel cell for my 48 coe ,I have about 1000 miles on it
.It cost around $60. to $80 dollars to make, you can make one too
The lower link is how to make one,you get better gas miles ,cleaner, and cheap to make ...
 Fuel consumpsion went from 16 to 23 per mile and the motor runs so nice and more power.
http://waterpoweredcar.com/hydrobooster.html
How to make your own Hydro Booster