Just returned from 2200 miles on the road. 875 each way from Austin area to Tucson and driving around Tucson and at way stops. Grand average mileage was 14.4 MPG. This is 2007 Duramax 4WD pulling 2005 Classic 28. Crusising speed was 62 MPH accorcing to GPS, indicating 64 on spedometer.
Some of the big climbs ate into the mileage. We topped 5000 east of Tucson and neared 5000 in west Texas. Bad headwind first day going and good tailwind last day coming home.
John W. Irwin
2005 Classic 28 "Sabre-Dog III"
2013 Silverado 2500HD Duramax/Allison LTZ
WBCCI #9632, TAC TX-10