I purchased this to hopefully increase the MPG in my 2008 Chevrolet Silverado 5.3 Flex. I have had the filter in for almost 4 full tanks of gas with 0 increase in MPG. I am disappointed in that however, I do like the fact that I will never have to buy another filter again as long as I clean this one regularly. I do feel that it allowed the motor to open up a bit, it does have slightly better throttle response.