I have a 2009 Gmc Dmax. Have had many other diesels, this is by far in stock form the best of the bunch, EXCEPT it gets the worst mpg towing of any of them. Empty on the highway it is about as good as any. So my question to any one that has expertise in this, is there something that can be done to help the the towing fuel economy. I'm not young and don't want noise, want to be able to hear whats going on in the back seat. Don't want to have the dealer throw out the warranty the next time I go in for an oil change. I don't need more power, it pulls my 26' foot camp trailor and my 6 place open trailor just fine, but would like to get 13-14 when towing like I used to get.
So I don't want to start a brand comparison, just some friendly advise if you have some.
So I don't want to start a brand comparison, just some friendly advise if you have some.