The 626 intake mani has a smaller air chamber so even with no "performance" to be gained given the same amounts of everything else then the smaller chamber has a smaller amount of air to move therefore it will move the given air faster therefore it will have a beneficial effect even if it is small and not noticeable also it depends a lot what else has been done to the vehicle plus there is the added bonus of it cleans up the bay and makes more room for other stuff and there is an audible change to the engine too however I do agree with hornsfan that SU is a little over priced.