I have the above with the tow package. While towing boat (5500lbs) half of my 200 mile recent trip used 12 gallons of gas while the 2nd 100 miles burned 20 gallons. Both legs were using towing mode and cruise control at 70mph on highway in FL. 1st leg noticed tach at 1900rpm, and 2nd leg at 2800. Truck did not want to go into higher gear. I tried using manual shifting, in and out of tow mode nothing seemed to help. Chevy dealer says everything is ok. Anyone with similar experience or knowledge on this issue? Thank you.

 

Welcome to the forum.

Sounds like it didn't go into OD on the 2nd leg.

 

Has it gone in to higher gear while towing since?

 

Left it in WPB for upcoming keys trip so haven't tried it but will shortly. Didn't know if there was a workaround to coax her into OD.