I understand that the low octane map is used in cruising situations where you would be under 3200 Rpm. Then high octane maps are used at WOT where you are well above 3200 Rpm. So if the JWT program retards the timing using the low octane map when the car is under 3200 rpm which is the only time the detonation sensor can sense detonation....how is that different then what Ash's program does??? And the funny thing is the ECU and the sensors is what controls that. JWT and Ash only control the fuel and timing in the different maps. The only way I could see a porblem is if JWT advanced the timing extremely in the low octane map and I just don't see that happening.