Chevy and GMC Duramax Diesel Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
My question is if there is any way to tell how much DEF is in the tank. I have had the truck just about a year, in August I did need to put some in, the message center said it was getting low. I was doing to towing on vacation pulling my fifth wheel trailer. I know that when the truck works harder the more DEF is used. Since that time I have not put any in the tank, the system says level is OK. I have probably driven 6,000 miles since then and no messages that more DEF is needed. I guess I can just trust the system, but I am curious about the amount being used. I will be heading out for a long trip in another 6 weeks, I just don't want there to be any problems. Suggestions? or am I just worried over nothing?
 

·
Premium Member
Joined
·
1,302 Posts
It will go from OK to a percentage. I pick-up two 2.5 gallon boxes of Peak Blue Def from Wally World and throw it in the bed when I know it's getting low and I'm towing heavy. What year is your truck? The newer models have a larger Def tank.
 

·
Registered
Joined
·
619 Posts
I was going to start a thread about this very subject but I’ll just hijack yours >:)

I’m in the exact same boat, bought my truck last March. I assume the dealer topped the def off but I never actually asked. Sometime back in the summer I got the % message so I added one 2.5 gallon jug and nothing since. I’ve put almost 8k miles on mine, most of that driving around on the farm or quick trips to town with the occasional long trip or tow. I can’t remember the mileage since I topped off but it seems like I should be long overdue for more def? 'dunno;
 

·
Registered
Joined
·
45 Posts
A general rule of thumb is approx one gallon of DEF for every 750-1,000 miles of normal unloaded driving. I've had mine go through as much as a gallon every 300 miles with a big trailer, lot's of hills and 80 MPH speeds.

If you purchased your truck new and used the dealer for the first couple included services (or Certified Pre-Owned maintenance) a couple gallons of DEF is included with the oil change so it may have been topped off without you knowing it.

I'd be really surprised if the truck went 8k miles on 5-6 gallons of DEF.
 

·
Registered
Joined
·
619 Posts
Mine was used, and like I said I assume the dealer topped it off before I bought it. Bought it end of March, added 2.5 gallon of def in July or August (I remember it was miserable hot outside) and I’ve not had to touch it since. The 8K is total miles since I bought it and I don’t remember how many of that was before/after adding the fluid but I realized the other day and I should be due for some. I was just wondering what the normalish interval is for most people.
 

·
Registered
Joined
·
619 Posts
Well, turns out I was right, I was low on fluid, like EMPTY. The def gauge in the truck was stuck on full, truck ran dry on def and caused a trip to the dealer and 18 days without my truck.
 
1 - 8 of 8 Posts
Top