Guess I thought wrong. I seem to see a lot of complaints on their DEF consumption when towing - though the ratio should be the same as fuel use.
A friend that runs GMC's sure does complain about his DEF usage but is vague when asked about actual MPG.
I get the same complaints from my GMC friends - but theirs is a little worse -
At random, they get failure of the DEF system, and the only way to get out of limp mode is to replace the def pump (and have the dealer reset it). I've searched for the alfaobd type software for their truck...but I don't think they're as lucky as us.
Regardless, in my 3 years on this Ram, they've done 3 DEF pumps, 2 fuel rail sensors, and at least 1 fuel pressure regulator (which all require everythign on top of the motor to come off for repair...)
Yet they still want their GMC... /foreheadslap
Oh, and they live in CA, where you can't get your registration renewed if you have a CEL... (even for something as simple as "fuel pressure high too long on deceleration".