i donot know why people are knocking k/n filters-----------been using them on my 2000 gmc truck for 9 years -----1984 goldwing for 17 years----1999 chevy suburban for 4 years---and will not go back to paper filters as long as i am driving ---------just have not got arount to getting one for my 1990 toyota dolphin---but i am going to get one before i go camping again ----everyone has their opinion and i think they are worth the investment troyrobo