1614 miles and the 1000 mile DEF warning came on. So much for the it lasts 5000 miles. No I have not been towing anything. Dealer must not have filled it.

I bet it wasn't filled before being delivered to you. I have an Uncle and close friend both with 2011 Chevy's and both just had oil changes at 5000, DEF only took 4 gallons on both trucks to get to the filler neck. That is with towing and a mix of town and highway driving. BTW, my DEF tank was filled for free when I bought the truck, have heard of some being charged.

I had to add DEF at 1600 miles also. I didnt get any warnings at all.....I started my truck and the DIC said "Engine power reduced".

My engine started and ran as normal and I added 3.5 gallons. Still not sure if it needed more, but that is all I could find in town.

Add 13 litters to it to fill it, return to the dealer for your free jug of it, should have been done as the plates were going on it...

Should've been filled up by dealer. Mine was.

like everyone has said..should have been filled

If im am not towing mine goes through a gallon every 1,000 miles but I towed on a 3,000 mile trip took 5 gallons and i had no 1000 warning so something is not right

I just picked up my 2011 Sierra 2500HD LML, and the service manager indicated that filling the DEF tank was part of the PDI (pre delivery inspection). He said they come with 2 gallons from the factor, and the dealer is to add 3 gallons. He said they don't fill it completely full so that there is room for expansion. If yours ran out, they did not do their PDI properly. I wonder what else they didn't check before delivering that new truck....

1614 miles and the 1000 mile DEF warning came on. So much for the it lasts 5000 miles. No I have not been towing anything. Dealer must not have filled it.

Dealer admitted they screwed up and did not fill it. They will top it off when I go in.