Do the Air Foils really work? do they make a difference? is the difference worth the price?i want to buy one but am unsure.

 

In various literature, they seem to make some gains, but with the little gains they do make, it won't be very noticable when behind the wheel. People sell them at a decent price on here sometimes though, it may be worth a shot.

 

Little bits add up, especially when youre trying to wring every ounce out of something.

 

I bought one fore 15 big ones from someone on here. My car is stock minus a CAI. No difference what so ever.

If you have a blower, or turbo however, it may make a huge difference.

 

This site has dyno tests of a lot of the popular bolt-ons:

http://www.ws6.com/mycar.htm

It shows the particular airfoil he tested was good for 2.4 peak HP.