Increased boost from 24-25 to 27mmhg. Mileage increase three quarter mpg. Get up & go is increased & readily felt. HAPPY HAPPY

Converted to this system years ago. Just needed a new filter. Price was fair in comparison to similar in auto parts stores.

Riff Raff has the best products in the best price in quick shipping will always buy from them.

I keep coming back to this site! The products are quality and the customer specie is too.
Just got done receiving my order of 3 6637 air filters. I've shopped around, and you can't beat these prices!
My air filters came as Donaldson brand.
Thanks, RiffRaff!

A little over priced

Installed a 4" exhaust with an eliminator pipe, this air filter and the truck ran like it was really breathing for the first time! Awesome bang for the buck!

High flow top quality. Expanded metal inside and outside so there is no worry about collapsing and getting sucked into your turbo. Definitely will buy another.......

The set up makes this air cleaner easy to install The air cleaner is of high quality and lasts a long time.

PS Service was quick.

I been using this air filter for years and been working great. RiffRaff has the best prices and fast shipping too cant beat that.