Air Filters???
Fleet Mechanic
Joined: Nov 2003
Posts: 1,372
Likes: 14
From: West Cornwall, CT
If your stock air filter is loaded up, replacing it with any type of new filter will help fuel mileage.
A new stock air filter works well and I have never seen a mileage increase with aftermarket units. Engine noise *does* increase with some of the low restriction aftermarket filters, but extra noise does not equal extra power or better mileage.
Lou Braun
A new stock air filter works well and I have never seen a mileage increase with aftermarket units. Engine noise *does* increase with some of the low restriction aftermarket filters, but extra noise does not equal extra power or better mileage.
Lou Braun
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
The oiled style filter elements do pass more air than the stock filter but they also pass more dirt. If you have a mass air vehicle an open element filter under the hood will actually reduce milage.
More Turbo
Joined: May 2008
Posts: 585
Likes: 11
I'm not a fan of K&N products. I work as a technician and too many times I've seen newer OBD-II vehicles come in the shop with codes PO171 and PO174 (lean exhaust, bank 1 and bank 2). Open the hood and sure enough, there's a K&N installed. Despite claims to the contrary by K&N, oil from the filter contaminates the mass air flow sensor which causes the ECM to alter the fuel curves based on false readings. GM has already issued a service bulletin advising technicians not to honor warranty claims if the vehicle has an oiled air filter because of this.
