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Phantom 4D Enthusiast

Phantom 4D

Posted
Posted

Anyone having issues with the DEF gauge? 

Mine was down to three bars. I filled per the manual which brought it up to full. I did a 1000 mile round trip, then driving it around town. It was down two bars after the trip.

I've driven a at least 1000 more or les since the trip. It's still at two bars. I really don't know if I trust it. But don't want to go into limp mode on the road. 

 

redwngr Senior Enthusiast

redwngr

Posted
Posted

Gauge can be misleading, for sure. 

DEF is used as a ratio of the fuel burned -- should be about 2%  - so about 2 gallons of DEF for every 100 gallons of fuel.

 

My first DEF truck, was a 2011.   2011's didn't have a gauge at all -- just the 1000 mile to empty and 300 miles to empty warnings.

 

Anyway --  when they do get to empty they then start a 500 miles to speed limit countdown which gives lots of time to get def.  Most are going to need fuel within 500 miles anyway, and if diesel is available DEF will be available too. 

 

I've intentionally taken my L5P and LM2 trucks to 'empty' just to see how the messages work.

Yes, I wasn't far from home/rescue if things went south. 

 

Haven't been able to make that happen (yet) with this LZO --  but I have got it close, and I fill at a commercial, metered, bulk location so I can get a better handle on how much DEF it is using. 

 

Truck is running better than 29 mpg lifetime, and I've added def about every 7000 miles. 

 

 

image.png.1e84b207b59eb4477cddc0dfddf41657.png

 

Lifetime fuel was running 29.6 when the last def fill was done

 

29.6 / 1379 x 100% = 2.1% 

 

Last fill, only the last partial segment was still 'on'.

image.thumb.jpeg.6a406ca43828f78f13aff106f5c74a5d.jpeg

 

 

 

Phantom 4D Enthusiast

Phantom 4D

Posted
  • Author
Posted
On 9/10/2024 at 6:17 PM, redwngr said:

Gauge can be misleading, for sure. 

DEF is used as a ratio of the fuel burned -- should be about 2%  - so about 2 gallons of DEF for every 100 gallons of fuel.

 

My first DEF truck, was a 2011.   2011's didn't have a gauge at all -- just the 1000 mile to empty and 300 miles to empty warnings.

 

Anyway --  when they do get to empty they then start a 500 miles to speed limit countdown which gives lots of time to get def.  Most are going to need fuel within 500 miles anyway, and if diesel is available DEF will be available too. 

 

I've intentionally taken my L5P and LM2 trucks to 'empty' just to see how the messages work.

Yes, I wasn't far from home/rescue if things went south. 

 

Haven't been able to make that happen (yet) with this LZO --  but I have got it close, and I fill at a commercial, metered, bulk location so I can get a better handle on how much DEF it is using. 

 

Truck is running better than 29 mpg lifetime, and I've added def about every 7000 miles. 

 

 

image.png.1e84b207b59eb4477cddc0dfddf41657.png

 

Lifetime fuel was running 29.6 when the last def fill was done

 

29.6 / 1379 x 100% = 2.1% 

 

Last fill, only the last partial segment was still 'on'.

image.thumb.jpeg.6a406ca43828f78f13aff106f5c74a5d.jpeg

 

 

 

Thanks for the info. I'll keep an eye on it. When I got the truck last year, the salesman and service manager said DEF should last until oil change. That didn't work out. I never listen to what they say anyway. 

  • 8 months later...
Z45 Senior Enthusiast

Z45

Posted
Posted

Mine was down 3 bars so I added a gallon and the gauge never moved for some 3 days and 1/2 doz starts. Then one morning I noticed it was showing full and been on full now for about a 1,000 miles +-.  But in the past I seen it drop 2 bars over-night.  So they need to refine this for sure, seems to be overly complicated.    

redwngr Senior Enthusiast

redwngr

Posted
Posted

I'd suggest adding def when it's near the bottom,  instead of near the top. 

 

 

 

parthery Enthusiast

parthery

Posted
Posted

I usually wait until mine drops below the 1/2 mark and then, if I'm at or near a truckstop with Bulk DEF I'll stop and get it.  As soon as I restart the truck it shows Full again.  I think I read somewhere that if you fill it before it hits the halfway mark, the sensors get confused and it takes a minute for them to self-calibrate.

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