Review on K&N Engine Air Filter 33-2154: High Performance, Washable Replacement Filter for 1996-2008 Subaru (Impreza, Forester, Legacy, Outback, and more) by Ronnie Staver

my gas mileage has dropped to 20-22 in the city when i was lucky it was 15-17. After replacing the old dirty air filter, I felt and heard the difference from the engine with the new K&N filter. I'll have to wait and see how much my mileage improves. I use K&N filters in all my family's cars, they are cheaper in the long run, after 36,000 kilometers the filter pays for itself in just one filter change, not counting the increased fuel consumption and the time and labor saved when changing the air filter. Most air filters need to be changed every 12,000 to 24,000 miles and cost $10 to $15 each.