Review on Engine Air Filter Performance Replacement Heavy Duty & Commercial Vehicle Equipment by Carl Mayes

I've been using K&N for a long time. I install their air filters on all types of cars. This particular filter is for a 13" Donelson engine air filter canister. It is most commonly used on Peterbuilt 379, Kenworth W900 and Freightliner Classic Class 8 trucks. The big problem lies in the design of this K&N filter. Unlike any other filter made for this application. where the bottom of the filter is closed, K&N has converted their filter to a filter tube. This does not work in the applications described above. There is a drain hole at the bottom of the 13 inch engine air filter housing. It is also planned to install a rubber grommet for the drain hole. Splashes from the front wheel also end up in the air filter container with the bushing. This in turn saturates the filter element and causes severe suction restriction. If you work in medium to heavy rain, your truck will accelerate slower and use more fuel. In general, this filter gets the lowest rating due to a design flaw.