I drive a 1993 Chevy Silverado with a 5.7 v8 engine. I have installed a Super Cell on my truck with a PCV Valve Inhancer & have gained 6 mpg. Some times I get 7 or 8 mpg better. It verys. I have had the unit on my truck for 2 mo, & have had no problems with my truck from it. Only good things.