Unless you live in Germany with an autobarn, or you are building a race car. Then performance is worthless, unless you are looking for a little extra for overtaking.. The fact is, we drive on roads dictated by speeds that are governed.. I for the life of me could never understand why people would buy a 4 cylinder vehicle to then try and turn it into a rocket ship, to only be held back by engine size and set speed zones? A tune up is fine, and some work on the exhaust for cosmetic sound, is fine. But you are better off with just working on the cosmetic of the car.. Have a nice ride that looks good... Save your money...