when do you guys fill DEF??

[ram5.7hemi]

just wondering when everyone fills the DEF? do you let it get low or was until you get a warning? or always keep it topped off? purchased a CTD a week ago. the def was just a little low but when i asked them to top it off when the topped off the diesel fuel they said its recommended to wait until it gives you a message or the computer might have issues and get confused or something...

 

[Hemipower392]

when ours is 3/4ths of the way full we fill it back up because it takes a whole container of DEF at 3/4ths of a tank.

 

[CDN Ram]

I allow mine to go down to the point where the warning comes on. I do this so I try and ensure that as much of the old DEF is out of the system prior to adding more. DEF has a limited shelf life, as I drive my RAM very little the lower I can get it prior to refill the better. I also only add a gallon or two at a time. again for the same reason.

 

[SouthTexan]

I fill mine up at the pumps once it gets to about half or a little less. It will usually take about 4 gallons to top it off at that point. Since I now have an 84 mile a day commute, that goes fairly quickly.

Who ever told you that you will mess up the sensors when filling is telling you a bunch of bull. DEF does have a shelf life of about 1 year if stored below 90F, and the stuff at the pumps is just about guaranteed to be more fresh than the jugs.

 

[BossHogg]

I allow mine to go down to the point where the warning comes on. I do this so I try and ensure that as much of the old DEF is out of the system prior to adding more. DEF has a limited shelf life, as I drive my RAM very little the lower I can get it prior to refill the better. I also only add a gallon or two at a time. again for the same reason.

This is the same strategy I use since the Cummins is only used when we tow the fiver.