I have a 1997 VW Golf Diesel and have been a happy Greasecar customer since October, 2007. I installed the system, with the microcontroller (Copilot), myself (I'm only moderately mechanically inclined), and I went with the larger 15 gallon tank. Since October I've driven approximately 15,000 miles on waste vegetable oil, and it's been smooth as silk, with no issues. I live in a cold climate in Ontario, Canada. I've got a French Fry stand guy giving me his oil.