Join Date: Oct 2010
Location: Victoria, B.C. on Vancouver Island
We have a 2011, GMC 3500, crew cab, short box, SRW and we tow a 12,000 lb Montana
fifth wheel. Just came back from spending the winter down in AZ and CA. We ALWAYS
tow at precisely 55 mph, it is the law in CA. We were getting 12 to 13 mpg in the mountains, and 15 on the flat without winds. We have had 24.9 empty at 60 mph.
Please note all these figures are hand calculated not off the DIC and using the Canadian