Rookie Diesel Owner
Posting this for my hubby: I recently bought a 2014 GMC Duramax Diesel. Previously pulled With a big block Chevy. Not sure what gear to use when pulling: Drive or Manual and I am not sure about th...
Forum Discussion
When I tow, its in tow/haul, even when not towing I do this. I use the exhaust brake when towing and when heavy, its full on. I use the manual mode when heading up the grades and I know from previous trucks I owned which had the exhaust temps monitored to try and keep it in the right gear and slow it down heading up grades to keep exhaust gas temps around 1100. She will purr all the way up. If you see engine temps rising to fast, down shift and slow it down or you will over heat, and by all means turn off the AC
