Review on K&N Cold Air Intake Kit for 1990-1993 MAZDA Miata: Boost Horsepower with High Performance 57-5001 Kit - 50-State Legal by Ben Chase

I really like my new K&N FIPK. While not a true cold air intake, it makes a noticeable difference, just like one. The installation instructions could have been better, but overall it's not too difficult. While this doesn't give you a huge performance boost overall, it does offer good value for money. Other pluses include improved gas mileage (about 1 mpg), improved engine sound and longer service intervals.