I traded for a 2012 GMC 2500HD diesel in Oct '14.....I have been told by a couple dealer service centers not to "top off" the DEF tank...let it run down to the warning, which I understand means there is still about 2 gal left, and then fill it back up to full. I haven't understood the reasoning in that. Does anyone know?
Lloyd & Kathy & Kit(17 yr old cat)
2014 Forest River Cedar Creek Silverback 33RL
2016 Chevy 3500HD Z71 LTZ 4WD Crew Cab, DuraMax/Allison.
2014 - 38 nights/3500 mi.
2015 - 66 nights/6260 mi.
2016 - 33 nights/4707 mi.