Hi Gerald, glad the MPG remedy is working 4 you. You are indicating a nearly 20% improvement in MPG. 'course, we're out of Winter now too...Are you referring to the Somender's groove's for the cyl. head? Reputed to work, but I've never done that.
I think you are right about the ECU learning each time the engine is started. The Gadgetman Groove should give added gains as well, will watch for your results!
Tracy G