How often do you top up your DEF?

Never wait till E, as you'll derate and be stuck doing 5mph down the highway lol. Depends on the def tank size, at 22gal I normally top it off every other day when I'm fueling.

 

I like all the added cost of Def emissions maintenance. But I got out of that headache and back into my groove 2000 379 well kept will drive till wheel fall off. It's okay just drink that fuel so it's a deal

 

Every second or third time I fill up. in the last 30k miles (since I started keeping track) I get 311 mpg, so it lasts for quite a while.

Try not to let it drop below 1/3 left. Preferably 1/2. If it starts running dry, the truck will derate and you will hate life. Of course you could carry a couple gallons with you just in case, but it's pretty easy to top it off every few days.

 

I have a question about that while everyone is on the subject. I'm so green my licence still has wet ink so pardon me if it's silly.

We had pre DEF trucks in school but the one I'm gonna be driving has DEF and they barely touched on it in school. What is the purpose of regen and when is it best to do them as far as time management goes?

 

I'll top off at half (or less) ...usually about 2000 miles, generally it takes about 8.6 gallons at the 2k point.

 

Your truck will auto regen in most cases(10 min). I get stuck doing a manual burn if the truck is running over 24 hours without moving (45 mins). You won't really have much say as to when it happens so when she starts roaring you let her do her thing. You won't be able to anticipate it and do a pre burn, she will only let you burn when she's ready.

I full Def every 3 or 4 days. You can go longer but if you run out your destroying your engine and sometimes will be stuck. One more thing, when your somewhere and it wants to do a burn, take the time to do it. If you sit a long time, hook up to your load and then the light pops on, it is possible to drive and burn it off under a heavy load. I wouldn't recommend it though. I had a friend that drove this way and after 150k miles his truck was being towed to a FL dealership to get the Def filter replaced. A normal filter should last 300k, maybe a little less, if you take care with burns.

If you ever wake up an hour late and are an hour late for an app, you just tell dispatch you had to do an engine burn. They can't argue you on that one !

 

My truck drives 700-ish miles a day. DEF is re-filled about twice a week. I used to wait until it was down to 1/4 tank and top it off.

 

I think a Regen is one part of the exhasut getting hot enough to clean another part of the exhaust system. To me it's just an additional tank to re-fill from time to time. I've been in a DEF truck since 2012 and other than re-filling the DEF tank all I notice is a funny light comes on every so often. I do nothing and it goes out. Our only instructions were to only get DEF at the terminal, never run out of DEF, and NEVER put DEF or Diesel in the wrong tank.