DEF Mileage
4-25-2015. For anyone who is interested - I just posted an update on page 3 with my latest mpg after just refilling the DEF tank yesterday. +++++++++++++++++++++++++++++++++++++++++++++++++++++++++...
Forum Discussion
A friend of mine has the same truck as you but short box. He hasn't calculated his DEF MPG but told me it was WAY up there. I am blown away with your calculations and it doesn't seem possible while towing. My GM while empty gets about 1200 DEF MPG and 18 Fuel MPG. When towing my Fuel MPG is an average of 11 and my DEF MPG is in the area of 6-700. As fuel mileage drops...DEF consumption goes up. The more fuel you burn, the more DEF you need to drop emissions.
