DEF Usage

[Compression-Ignition]

Here's mine, no towing just regular commuting. More reason to tune and delete, maybe use that space as aux fuel storage.

That doesn't seem right at all. It's like you've been in regen this entire time......

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[Megatron JLU]

That doesn't seem right at all. It's like you've been in regen this entire time......

I've never seen the regen come up. Not sure why it's eating it up so fast.

 

[VABarn]

I know when I bought both my Duramax Colorado and this Wrangler, the dealerships stated they topped off the DEF prior to releasing it. It seems they don't come full from the factory.

Just a guess, but Megatron, is this the first time you have looked at that screen? Maybe it has always been low?

 

[Megatron JLU]

I know when I bought both my Duramax Colorado and this Wrangler, the dealerships stated they topped off the DEF prior to releasing it. It seems they don't come full from the factory.

Just a guess, but Megatron, is this the first time you have looked at that screen? Maybe it has always been low?

It is, maybe you're right. I'm going to top it off today and check again in a week.

 

[Compression-Ignition]

I've never seen the regen come up. Not sure why it's eating it up so fast.

I think these newer diesels often times do not notify the driver of a regen occurrence (perhaps never until they get interrupted many times).

I've never seen the regen come up. Not sure why it's eating it up so fast.

I know when I bought both my Duramax Colorado and this Wrangler, the dealerships stated they topped off the DEF prior to releasing it. It seems they don't come full from the factory.

Just a guess, but Megatron, is this the first time you have looked at that screen? Maybe it has always been low?

Good point.

 

[Gonzanc]

I know when I bought both my Duramax Colorado and this Wrangler, the dealerships stated they topped off the DEF prior to releasing it. It seems they don't come full from the factory.

Just a guess, but Megatron, is this the first time you have looked at that screen? Maybe it has always been low?

I stated this earlier, but when I received my 3.0 with 29 miles on the odometer, there was a "def low message" and the dealer filled it up prior to me leaving the lot, which means they are being delivered with a minimal amount of def fluid.

 

[Karl_in_Chicago]

That doesn't seem right at all. It's like you've been in regen this entire time......

Maybe it's the driving sideways?

 

[JLURD]

Here's mine, no towing just regular commuting. More reason to tune and delete, maybe use that space as aux fuel storage.

Yea that’s bs if the meter is accurate and you’re certain it was topped off at delivery. It certainly seems like they’re not truly full from the factory and dealers aren’t going to top it off unless asked to...even then they might go by the onboard meter and say no.

 

[JLURD]

That doesn't seem right at all. It's like you've been in regen this entire time......

DPF regens won’t cause a 5x increase in DEF usage in the SCR system. Even if he was idling a lot and running around town exclusively, the DEF wouldn’t be this low. My money is on less than full from factory, with a bad sensor being a distant second.

 

[JLURD]

I stated this earlier, but when I received my 3.0 with 29 miles on the odometer, there was a "def low message" and the dealer filled it up prior to me leaving the lot, which means they are being delivered with a minimal amount of def fluid.

They sure are...that was my DEF gauge at delivery.

 

[Eeshasdon]

Sounds like this is another check item during dealer pickup. This way everybody knows to check this before they drive off. I would think this should be a PDI check. Probably good to post this in the production section or start a new "what to look for at pickup" in a new section.

 

[2020 Diesel JL]

Truck driver here def freezes during very low outdoor temps. The less def you have the more is prone to crystallizing. I would always have two or three gallons in my truck keeping it warm in the cab just in case. I learn that lession the hard way my truck went in to limp mode and had to drive 15miles at 5mph to the nearest gas station.
Always top it off in my opinion does not hurt
Example of what it looked like inside

DEF freezes at 12 deg fahrenheit, The DEF system has heaters in the tank and all fluid lines. During cold weather the DEF system is not used until the DEF is warmed up by these heaters so it will never shut a motor down because its frozen. It will if the heater circuit fails even if it's 100 deg outside. That is a system that I think they could program differently. Living in Fl you would think a check engine light would be fine since the DEF is not and could not freeze but nope it will shut the truck down.
DEF consumption is based on outside temperature, load and driving habits. Pull a trailer in the cold and you will use 4 times the DEF as running around with no trailer and warm temps. Come summer you will think there is something wrong with your DEF system because the level will seem to never move off full.

 

[2020 Diesel JL]

Is all DEF the same?

There are some companies making poor quality DEF. Beware of white box or no name DEF. It could make for a bad costly day. I use only Blue DEF made by Peak. Never had a issue in any truck. Just remember DEF has a shelf life and needs to be stored out of the heat and sunlight. Warranty will not pay for poor quality DEF repairs.

 

[Melny67]

My order invoice says 4 gallons of fuel from factory. The dealership filled my JL before I picked it up. My guess is the def tank has a default amount as well.

 

[Melny67]

DEF freezes at 12 deg fahrenheit, The DEF system has heaters in the tank and all fluid lines. During cold weather the DEF system is not used until the DEF is warmed up by these heaters so it will never shut a motor down because its frozen. It will if the heater circuit fails even if it's 100 deg outside. That is a system that I think they could program differently. Living in Fl you would think a check engine light would be fine since the DEF is not and could not freeze but nope it will shut the truck down.
DEF consumption is based on outside temperature, load and driving habits. Pull a trailer in the cold and you will use 4 times the DEF as running around with no trailer and warm temps. Come summer you will think there is something wrong with your DEF system because the level will seem to never move off full.

I had heaters fail on me leaving me on the said of the road in the winter before not fun let's hope the JL comes with a better heater then my peterbuilt and Freightliner.

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