Community Forums

pgrennan3 · 01-26-2022, 06:31 AM

Considering, price, ease of finding, quality issues?

Maybe I am overthinking this...just would like some experienced responses before I pick up my new Renegade.

Thanks in advance

dizcom · 01-26-2022, 06:53 AM

Nice rig! DEF is DEF. There's only one formula no matter who you buy it from. There's a more expensive DEF starting to show up (gold or something) and it has additives that are supposed to make it better, whatever that means. The rest of it is all the same, no matter if you buy it at the pump or off the shelf. You want fresh DEF as much as possible. Busy gas stations that sell a lot of it are more likely to have fresh DEF because of turn over. If you buy it off the shelf there's a date on it that says when it was made.

Don't fill your DEF tank unless you intend to use it. Fresher is better, so don't let the DEF in your tank get old by overfilling it and not using it. If you think of it like fuel and always want a full tank, you'll have a full tank of old DEF and that can cause problems. The only time our DEF tank was full was when the dealer filled it when we picked up our rig new. I put in only what I need so my DEF is always fresh onboard. The only thing I watch is that it doesn't go below 1/4 tank so that I don't start getting low DEF warnings. The tank is empty when the rig is stored. DEF is usually really easy to find. Walmart, auto parts stores, gas stations all carry it.

Cat320 · 01-26-2022, 09:06 AM

As noted, DEF is DEF. However, it has a two year shelf life if stored between 23 and 68....if stored between 10 and 90 it is one year. I don't stock up on it, I buy what I think I'll use soon...with a little fudge factor.

vettenuts · 01-26-2022, 07:59 PM

I don’t buy at a fuel station, rather from the store. Not sure what the Blue Platinum is that came out, but a few people have had issues after using it so I just avoid it. I have used the regular Blue that you can find in Walmart, Oilzum (local in New England) and Cummins. Cummins actually has a very good price on it. I usually pick some up when I stop for my spring service.

As previously stated, look for something recently made as there is no guarantee on how it’s been stored and depending on storage conditions the life can be quite short.

pgrennan3 · 01-26-2022, 08:02 PM

How do y’all estimate how much you need? Miles? Hours? Gallons of fuel?

**Camp CA** · 01-26-2022, 08:18 PM

DEF is DEF........I try to fill at the pump and when I cannot do that I fill Blue DEF.

tmandoug1 · 01-26-2022, 08:27 PM

Refractometer for all store bought DEF. Never bought at the pump....hassle big time. But I am in and out that the trucks stops....those guys need to do their thing. Peace.

Toribk · 01-27-2022, 03:48 AM

pgrennan3,

Your new rig will come with a DEF guage presumably at the dash (digital lights) and a typical analog guage on the tank itself.

Each rig will vary on consumption, so it will be trial and error on your first trip to see what your usage is going to be with the coach.

I use the regular Peak DEF Blue (2.5 Gal) you can find anywhere...including Lowes and Homr Depot and I lose 1 of my 4 green dash lights on the gauge for each 2.5 gallons consumed or roughly 700 miles with my particular coach (Cummins ISC 380) and driving 62 mph average towing my Jeep Trailhawk.

Your mileage may very, but make some notes on your first trip and you'll be able to figure your DEF usage per miles traveled from there.

In my maintenance regimen, I have never allowed the DEF tank to go below half-full and have never had any issue with my aftertreatment system.

Despite what Cummins recommends, I change my DEF Dosing Filter once per year as part of my routine maintenance program.

Congratulations on your new rig!