Originally Posted by Mad Dog 64
Ok... there has got to be something to this... My mileage has gone from 39 to 41 MPG. It is only 2 MPG, but it is an increase. Does that make sense?
It's possible since the ECM might be sensing detonation and retarding the timing and thus cutting the power.
The best way to tell is to datalog it so you can see if it is sensing detonation.