Originally Posted by KmndntKlink
I'm in the same boat, seriously considering an ESS tune, but their tune is reversable, so it would put all of these back in pilace. If you reflash stock before taking it in, wouldn't bmw not know? Or is there some log that records when the engine goes above rev limit & speed limiter that isn't wiped with the flash? Would really like to know how this works if there's any bmw techs or car engineers who know how ECUs work.
I'm probably going for it anyway tbh, it seems like a great mod to really trim everything up for not much $$$
As stated the max rpm and speed are stored permanently.
Love the ESS tune btw.