I know that a few of you have wondered what fuel mileage would be at the richer 13.8:1 AFR I'm running.
Just ran my first gas mileage test using the LC-1 Wideband O2. All the driving was on local trips, no highway, up to 25 miles per trip, some as short as 5 miles, plenty of lights.
I burned 2.48 gallons, for 106 miles. That's 42.7 MPG, give or take.
I still plan to take a highway trip and see what the mileage is.