Lesson learned ... these cars do NOT like low octane gas

[WolfpackS2k]

Originally Posted by wbradley

I read somewhere that knock is detected audibly (there is a sensor somewhere in the engine bay). This ECU uses considerable timing advance as the RPMs rise. Only reason I know this is that I have a timing advance gauge in Torque running on my dash mounted Nexus 7 tablet. For example, at idle the advance might be 11 degrees before top centre crank position and at 3500 RPMs it might be closer to 38 or 40. I would think the sensor would continue to retard timing until knock is supressed on a feedback loop. This way performance wont be totally ruined at 91 octane by retarding the same as if it was 87.

Pre-detonation is detected (heard) by knock sensors that are installed in the engine block.