I bought a ScanGauge II about a year before I found ecomodder.com. I didn't realize my Mustang had DFCO until I observed 9999 inst MPG on the ScanGauge II. About the time I found ecomodder.com, the ScanGauge II had helped me get my Mustang up to 30 MPG; with more improvements over the last 5 years since I found ecomodder.com. Current lifetime average is 29.9 MPG - 49.5% over EPA combined.
Instrumentation is the most
important mod because it helps you make the most
effective mod:
adjusting the nut behind the steering wheel.