Originally Posted by Roman@ESS
The M3 DME is an adaptive control system tuned or stock. It will always self adapt to the fuel being used in the vehicle. This includes the octane rating and quality of the fuel due to additives such as ethanol. You can vary the fuel used and the DME will adapt in an attempt to make as much power as it can while keeping the motor safe. This is why you see cars that run race gas typically gain power on the dyno without any changes to the tune.
Roman,when i got my tune i have mentioned that the fuel i use is 94. do you accommodate that when doing a tune to extra more power or you dont need to as the DME already adapts to it ? so is there anything call a 94 tune for an e92 m3 basically, or its the same thing as 91 tune because the DME will adapt to the higher grade.