Originally Posted by
mrx007
no offense to you people out there. but store bought additives dont do a damn thing. i can't remember if it was mythbusters or 2 guys garage but they did a test. and in most cases the additives killed your mpg's by sometimes up to 30% and did nothing for octane levels. but if someone has numbers to prove me wrong. please post. i wish that crap worked.
most of them only increase the octane level by a few points, the catch is, it takes 10 points to equal an octane number. The only one I've come across that actually ups the octane level is that NOS additive. There are three of them, and they are supposed to increase the octane level up to 60 points. So up to 6 numbers. If it actually does that much, and with how much gas, I've never tested. I do know that it increases the octane level some because I could advance the timing a little bit more than usual.
sorry, no "official testing" or anything with them, just what I've been able to read up on...