Hi, from what I can gather from mechanic friends and online reading, the K&N replacement air filters are designed specifically for certain vehicle models. And through these specific designs, air flow to the engine is increased. A more efficient engine is supposed to produce a little more torque, a little more horsepower, and i'm pretty sure a little better gas mileage. Visit their website for more product specific information.
www.knfilters.com
Good luck.
RB