I'm new to the DEF so I'm curious to how many mile you get per tank of DEF? I have 3700 miles on a half tank....

 

Depends on driving habits but that sounds about right, I get about 8-9K per tank, I tow a couple times per month.

 

5K on average so 1,000 miles per gallon,

 

More in the summer and more when towing. I add a 2.5 gallon jug when the DEF gets down to 1/2 tank.

DEF is such a non-issue.

 

I have 3200 miles on my truck since new and the DEF tank is at 1/4. I occasionally tow a 14,000 5th wheel trailer.

 

I'm at 3900 mi. DEF gauge shows about 7/8 full still. I had an oil change done at 1500mi., at that time the gauge showed full but the dealer topped it off anyway. It doesn't seem to use much DEF, but sure does go through the diesel plenty fast.

 

It varies a lot. I have gone as little as 1500 miles and used 2.5 gallons and as much as 5000 miles and used 2.5 gallons. Towing very heavy and empty seem to use the least. Towing about 12,500 with my F-450 seems to use the most. Not sure why but after about 50,000 miles this seems to be my experience.

 

Currently my DEF tank is just at half full with close to 10,000 km’s of driving, with 3,000 of those km’s towing our travel trailer. I’m really happy with how little it uses. A friend of mine recently had a new Chevy 2500 with the Duramax and he went through a tank in 3,000 km’s towing. I know they have a smaller tank, but he could literally see the DEF tank emptying as he drove. I’m pleasantly surprised as to how much of a non-issue the whole DEF thing has been in my case.

 

I'm just coming up on 5,000 miles on my new 2019 F-450 and the majority of that has been carrying our 6,000+ lb. slide-in truck camper, so at (or above) max GVWR! Just over 50% highway, the rest, country roads, smaller, northeast mountains going to and from campgrounds. I've filled it once with 4 gallons and it's currently at 1/2 full! Probably due to the constant load, I would guess. [Still getting great mileage on the diesel however... 12.5 loaded - 18.8 empty (compared to 8.2 loaded/11.4 empty with previous my 6.2l gas F-350)!]

 

Mostly in town driving, but some highway towing big fifth wheel, I average 1.6% DEF consumption to diesel burned.

 

I have 6700 and change on the clock and I just got the 500 mile warning last night.

 

3,500 miles on my 2020, 80/20 highway/city driving, ~1,000 miles of towing between 3,000 - 8,000 pound trailer and I've used about 3 gallons. I too have been surprised on how little it uses and it is indeed a non-issue.

 

I’ve got 20k miles on my 13 month old 2019 F-350 CCLB 4x4. I’m a full time RVer pulling a 9500lb travel trailer about 3/4 of the time. I have a camper shell and travel with the bed fully loaded. My truck tips the scales at about 11,200lbs connected. I get between 400-500mpg out of the DEF. I have resorted to dumping a 2.5gal jug of DEF in when the gauge nears 1/2 full. I carry a one gallon jug all the time just to be on the safe side in the event that I run it down too far.

I would highly recommend running the tank to empty once to experience the messages and alarms the truck gives. Just make sure you’ve got some DEF to add. One gallon is enough so long as you’re near a source for more to fill it up. I make this suggestion because of what happened to me. I added a gallon when my messages read “Only 30 miles till DEF is empty”. Upon adding the gallon of DEF, the gauge and messages DID NOT CHANGE. I asked my service department what was going on. They told me to cycle the ignition on and off several times while the truck was stopped. Sure enough the gauge came up to about 1/8 tank and the message and alarms ceased.

 

THANK YOU Sir- that's some great info to have! Awesome post...

 

I always refill the def tank with the truck running and the gauges keep up with the fill rate, and the dash light goes out as I fillerup. I put 6 gallons in this week - sitting on 100% now.