Mr. Ruck

I agree! The only warning that I receive is a 1,000 miles remaining message I usually pour a 2.5-gallon jug in it at that point, & wait till the next time it gives me the same message & repeat the process. The last time I decided to put two 2.5-gallon jugs in the DEF Tank to so I could fill it more than just partially. I got just shy of finishing the second jug when it puked all over the place, then had to close the filler cap & spray the passenger side of the engine compartment, & front fender down with water to rinse all that crap off of everything. You're exactly right about having some kind of measurement of actually knowing how much DEF is in the tank, or how much to add when it says 1,000 miles left. I can get a better estimate on how much diesel my tank needs to be filled just by the miles since last fill & how many miles per gallon I've averaged. Hell I can get my washer fluid figured out easier without spilling, & don't have to worry about getting that stuff all over my skin or worse yet, in my eyes. I guess we have to spend over $100k before GM will come up with a better design than what they currently have. i