I set a new MPG record over the weekend.
This was the seventh time I've driven my Mustang to southern CA for a family reunion party.
The six previous trips, I drove the speed limit (75 in AZ, 70 or 65 in CA). I would top-off in Flagstaff when leaving, then fill-up in Barstow along the way.(355 miles) MPG was usually high 28s to mid 29s.
This year I topped-off when leaving Flagstaff, and set the cruise control @ 65 MPH on the freeway. Around Kingman, I started "P&G-ing" the a/c compressor with a/c on recirculate. When I reached Barstow, my fuel gauge was at 1/4 and my dash display indicated 160 miles to empty, so I didn't stop. I pulled into the hotel parking lot in Foothill Ranch with the dash display indicating 22 miles to empty.
I filled-up the next morning:
average speed: 61 MPH
trip distance: 480.0 miles
Fuel pumped: 13.978 gallons
Tank average: 34.339 MPG