the "Adds up to" is usually accompanied with 'along with certain performance upgrades'. In other words, you won't see the hp gain unless you've already got things like exhaust and fuel upgrades. Honetly, with the NA, spend your time getting he looking cherry rather than milking a few HP out. you might squeeze a few extra out, but you will hit the point where HP gains cost a lot quick. Or just save up for a TT
