[Tag]

Originally Posted by Tag

I posted this question in the n55 forum by accident.

Now that I've found the right thread I'll ask again hoping someone here knows the answer...

I'm trying get some information on Stage 1 aggressive maps for AccessPORT regarding octane. The stock ECU can detect the octane level and adjust. For instance, if I put in 89 octane it will automatically detune itself to avoid damage from pre-ignition. If I run the 93 octane aggressive map and end up filling with 91 octane gas because 93 was simply not available in the location I was in would the reprogrammed ECU be smart enough to detect the drop in octane and adjust?

If I find myself in that situation I would just put in a couple of gallons of 91 until I was able to get to a 93 octane pump and not have to really much. I don't like the idea of sitting at a gas station flashing a map before I can safely drive off and then doing the same again after I refill with 93. That would be such a PIA.

I guess I can drive conservatively but it still sucks because you'll need to reflash to make sure you don't run into issues. I asked Cobb directly and this was what they said.

"Thank you for your inquiry. The DME would pull timing if it detected detonation, so in a sense it would "de-tune" itself. This is not an ideal case though as the detonation would have occurred before the timing corrections. The octane we recommend is the minimum that should be used due to the additional power we make. If you run into a case where the minimum octane fuel is not readily available, it would be best to flash the lower octane map and refrain from driving the vehicle aggressive."