I've become a little bored of my M5 so now I'm looking to increase the HP!!
I'm already running the MEISTERSCHAFT GTC + LXR PIPE which I'm extremely happy with ...
So I'm thinking about doing a stage 1 ECU tune with the factory DP's ...
However I've been going back and forth whether I should do the ECU tune or not but honestly I'm afraid of the following :
1. Can my dealer detect it the tune?
2. How reliable is the ECU tune?
3. Will there be a engine light?
4. In California we run 91 octane - will that be a problem?
5. Will I really FEEL a substantial difference?
6. What's the actual power increase?
WHAT ARE YOU AFRAID OF?