Brought one of theses fuel savers my side by side is useing half the gas it was without one my sister went to the big smoke the other day said she used about half the gas ment to save about 20% but it’s illegal to make anything that saves more then that only ment to work on cars made after 2001 as gas compeneys payed the car compenys to make cares use more fuel they only $38 nzd witch is half that for the USA worth looking into if you want to save some money on gas i brought 2 more for the ride on lawn mower and tractor they just plug into the derivative lighter socket in the car