purchased the car and found a conversion kit from a company in Massachusetts called Grease Car . The Melvilles then took the car and kit to an expert installer in their area and in no time , they were driving around -- with free fuel . The kit and installation cost about $ 1,000 each , and Melville says it took about 1 1/2 years to recoup that cost . `` We 're kind of playing with house money , because we 're driving on free gas , and it 's paid for itself many times over , '' he said . Melville , who is a writer , has driven the gas-free vehicle more than 60,000 miles , including two cross-country trips he 's written about in an upcoming book . Veggie car makes a cross-country road trip '' The converted car was outfitted with a 15-gallon tank . Melville says it gets about 20 miles per gallon , the same fuel economy it would have gotten with the original diesel system . But according to a recent editorial he wrote for The New York Times , Melville says his carbon footprint is cut in half while driving the
ASHEVILLE , North Carolina -LRB- CNN -RRB- -- Greg Melville 's neighbors in Vermont looked at him like he was crazy 2 1/2 years ago when he drove what he refers to as his `` vegetable vehicle . '' It 's a car that runs on vegetable oil instead of gasoline . Greg Melville converted a 1985 diesel station wagon to run on vegetable oil when his family needed another car . Back then , gasoline cost about $ 2.20 per gallon . Now that the cost of gas is nearly twice that , many Americans are starting to think that converting to a vehicle that runs on vegetable oil is n't such a bad idea . Melville , who now lives in Asheville , North Carolina , says the decision to convert a 1985 diesel station wagon to run on vegetable oil came about when his wife was in medical school and the couple needed a second vehicle . `` We did some research and found out that the old Mercedes engines were very easy to convert , just because they are practically indestructible , '' Melville explained . After he found a good deal online , the couple