Reviewed By Joseph F (Clinton, MD) Reviewed for a 2012 Mazda CX-9 —1/16/2014 4:47 AM
The difference between the stock filter and the K&N filter is dramatic. Stock filter was about 4.5 inches thick and I am shocked at how restrictive it was. The K&N is about 2 inches thick and really allows the air to flow. Also noticed an increase in mpg & power. Simple upgrade and works well.