DEF Consumption Rate
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Joined: Jul 2019
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From: Upstate, SC
DEF Consumption Rate
I've got a 2018 with 6.7L that I bought used with 27K miles. I had the oil changed at 30K miles and the dealer filled up the DEF. I'm a litte over 34K miles now and just got the warning that I had 500 miles of range on the remaining DEF so I pulled in a truck stop and filled it. All my milage is towing my boat, which isn't super heavy. Very similar in weight and profile to a larger bass boat, about 3,500 pounds trailer included. I am mostly towing on a highway running 68 to 70 on the rolling hills of upstate to midlands SC. The guy I bought it from said he usually made it to the 7,500 mile oil change interval between DEF fill ups so Ford had filled the DEF for him every time. I assume my increase in consuption is just due to the fact that I'm almost exclusively towing, and he was mostly driving to work and rarely towing. Just wanted to make sure that my consumption rate isn't unusual and I had something I should be concerned about.
Mountain Pass
Joined: Oct 2018
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I've got a 2018 with 6.7L that I bought used with 27K miles. I had the oil changed at 30K miles and the dealer filled up the DEF. I'm a litte over 34K miles now and just got the warning that I had 500 miles of range on the remaining DEF so I pulled in a truck stop and filled it. All my milage is towing my boat, which isn't super heavy. Very similar in weight and profile to a larger bass boat, about 3,500 pounds trailer included. I am mostly towing on a highway running 68 to 70 on the rolling hills of upstate to midlands SC. The guy I bought it from said he usually made it to the 7,500 mile oil change interval between DEF fill ups so Ford had filled the DEF for him every time. I assume my increase in consuption is just due to the fact that I'm almost exclusively towing, and he was mostly driving to work and rarely towing. Just wanted to make sure that my consumption rate isn't unusual and I had something I should be concerned about.
You're fine, 4k miles on a tank of DEF isn't anything to worry about. Depending on your trim level you may be able to display the DEF gauge so you can get a feel for your consumption. Personally I top off my DEF tank periodically like every few months. My DEF consumption increases considerably when I am towing my boat or camper in the summer.
Mountain Pass
Joined: Oct 2018
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My neighbor has a 2019 Chevy Duramax and has issues with DEF. He gets less than 500 miles on a tank of DEF towing. Chevy seems to have no answers for him. He's not pleased.
Mountain Pass
Joined: Nov 2019
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It could be very possible that the dealer did not actually top your DEF tank off but just put a couple gallons in it. I have found the gauges are not real accurate. Sometimes you could fill it just over half and it will show full etc.
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Joined: Jan 2020
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I've got a 2018 with 6.7L that I bought used with 27K miles. I had the oil changed at 30K miles and the dealer filled up the DEF. I'm a litte over 34K miles now and just got the warning that I had 500 miles of range on the remaining DEF so I pulled in a truck stop and filled it. All my milage is towing my boat, which isn't super heavy. Very similar in weight and profile to a larger bass boat, about 3,500 pounds trailer included. I am mostly towing on a highway running 68 to 70 on the rolling hills of upstate to midlands SC. The guy I bought it from said he usually made it to the 7,500 mile oil change interval between DEF fill ups so Ford had filled the DEF for him every time. I assume my increase in consuption is just due to the fact that I'm almost exclusively towing, and he was mostly driving to work and rarely towing. Just wanted to make sure that my consumption rate isn't unusual and I had something I should be concerned about.
The gauges seem to be wildly inconsistent. A buddy’s F250 shows DEF drop to half in his first 500 miles of filling it, then staying there for 5k miles, then dropping rapidly to empty.
There’s a good chance yours was not full...just indicating full.
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New User
Joined: Jul 2019
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From: Upstate, SC
I did wonder if the dealer really did fill it all the way. When I refillled it at the truck stop it cut off at just over 5 gallons. So I still had almost 2 gallons of reserve.
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From: Wyoming
My DEF gauge is accurate, eventually. I don't worry about DEF too much, so I don't track how much is used. My truck is used mostly for towing so I go through more than someone who doesn't tow.
I do add a 2.5 gallon jug when the gauge goes just below half. There have been some posts about the system getting stuck when the DEF level gets very low, even after filling the tank. So I keep it from ever getting to that point.
I do add a 2.5 gallon jug when the gauge goes just below half. There have been some posts about the system getting stuck when the DEF level gets very low, even after filling the tank. So I keep it from ever getting to that point.
Mountain Pass
Joined: Mar 2019
Posts: 133
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Sounds about right. I find it goes through a lot of def when I am towing light. Empty goes through the least and heavy towing it doesn't go through as much. I have gone through 2.5 gallons in about 1000 miles when towing light to medium with my F450 but I have gone as long as about 3000 miles when empty for 2.5 gallons.
BuhBye F450, I'm relaxin'
Joined: Feb 2009
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From: Plainville, MA
Sounds about right. I find it goes through a lot of def when I am towing light. Empty goes through the least and heavy towing it doesn't go through as much. I have gone through 2.5 gallons in about 1000 miles when towing light to medium with my F450 but I have gone as long as about 3000 miles when empty for 2.5 gallons.
Mountain Pass
Joined: Mar 2011
Posts: 162
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From: Southbridge, MA
I was beginning to think something was wrong with my DEF gauge. I have over 2000 miles on a full tank and it still reads full, and 100% on my idash. Keep waiting for it to start going down.