[johnmo]

After showing "OK" for the first 3500 miles or so, my DEF level in the DIC suddenly shows 35%. I'm not a fan of the "OK" level. Just show me a percent full or life just like the oil, fuel filter, and diesel tank.

Notification quirks aside, does this seem early to be needing DEF? I figured it would go 10,000 miles or so and it's looking like it will be about done before 6,000.

Maybe it didn't come from the factory with a full tank. Does anybody know the capacity of the DEF tank on the Gen2 models?

 

[MP81]

It is kind of annoying that it doesn't give you a level above 35% full, but it's probably due to it being unable to measure it actively, if I were to guess.

I'm going to assume the tank is smaller, but I can't say for sure as I have not seen any mention of its size. Given that the smaller engine (with a half-point lower compression ratio) should put out less NOx emissions, DEF usage should decrease somewhat from the 1st gen CTD. And considering the tank is no longer able to use the massive expanse that would be the spare tire well, it more than likely has to be a lot smaller.

 

[Tomko]

A couple of things that may help understand this situation:

1) DEF, like washer fluid and gasoline, is considered a consumable. And as such the reservoirs are not shipped from the assembly plant full. Only a nominal amount is supplied to allow the vehicle to operate during the delivery process. I suspect this has as much to do with shipping weight as it does with plant time and cost. It is the responsibility of the dealer to fill these reservoirs as a part of the pre-delivery inspection. But as we've seen, and especially for DEF, it is often 'missed' by the tech assigned the PDI.

2) The DEF level indicator is programmed by GM to show OK until the level drops to 35%. GM does this on all of its diesels. DEF has a limited shelf life of approximately one year. Once DEF 'goes bad' it will not fully treat the emissions and will set a code eventually preventing the engine from running in any useful way, in accordance with emissions regulations. I suspect that GM uses this OK until 35% level indicator as a strategy to prevent owners from needlessly topping up their DEF and causing a situation where the quality of the entire tank of DEF has deteriorated to a point where it can no longer properly treat the emissions and cause the vehicle to go into limp mode. The analogy I'd make is of someone who never lets their fuel tank drop below 1/2. At best, they're only ever driving around with 1/2 tank worth of fresh fuel, diluted with 1/2 of stale. Repeat that over and over for two or three years and you've got a problem with any perishable product.

 

[boraz]

youre overthinking it

fill it at OCI and drive

 

[johnmo]

youre overthinking it

fill it at OCI and drive

Well, yeah, I'll fill it and drive. We have a Flying J with DEF at the pump and it's on an alternate route for my usual commute, so that'll work out. Just wasn't figuring to fill it quite that often.

What's OCI?

 

[boraz]

Well, yeah, I'll fill it and drive. We have a Flying J with DEF at the pump and it's on an alternate route for my usual commute, so that'll work out. Just wasn't figuring to fill it quite that often.

What's OCI?

oil change interval

gen 1 tank is large enough to last thru OCI, just wild guess the gen2 is as well

even if not, 35% is lotsa fluid left, not gonna be stranded

 

[Cruz15]

What Tomko said and I can go 11,000 kms and still have way over 1/2 tank. Gen 1

 

[mkohan]

Maybe it didn't come from the factory with a full tank. Does anybody know the capacity of the DEF tank on the Gen2 models? 3,8 gal

 

[Jetblast33]

I'm at 3600 miles and mine just went to 33% , so added 2 gallons. Yes 3.8 is the capacity. Maybe not topped off when purchased.

 

[LiveTrash]

I read an article that says the Gen 2 Diesel may need a DEF fill-up every 4,000 or 5,000 miles. I've worked it out that on a completely full tank on my Gen 1 Diesel (17 litre tank), I can go about 12,400 miles. My large work truck burns about 4 litres of DEF every 620 miles. My Cruze gets a little better mileage on DEF than it, so it seems appropriate.

 

[johnmo]

I read an article that says the Gen 2 Diesel may need a DEF fill-up every 4,000 or 5,000 miles. I've worked it out that on a completely full tank on my Gen 1 Diesel (17 litre tank), I can go about 12,400 miles. My large work truck burns about 4 litres of DEF every 620 miles. My Cruze gets a little better mileage on DEF than it, so it seems appropriate.

I haven't seen the article, but I have seen the Gen 1 DEF usage number around 10k miles or so, which is why I thought it was possibly a little premature for my Gen 1 to be nearing a fill-up. I'm sure they've had to up the DEF usage to stay compliant with the EPA requirements. Thanks.

 

[Jetblast33]

Just a heads up, my DIC showed 36% today so topped off with exactly 2 gallons. Purchased at the local truck stop for 2.79 gallon. So far I have added 4 gallons since new and I'm at 5200 miles.

 

[johnmo]

Mine was down to 11% when I had my oil changed at the dealer today. They topped it off, though the service ticket says "2." It's not very specific about what I got 2 of, but I'm guessing DEF. Gauge shows "OK" now, but I doubt the tank is full based on what others have said about it.

 

[johnmo]

I didn't make it to my next OCI before needing DEF. It seemed to kind of suddenly need filled because I don't remember seeing any notifications before it started reporting under 300 miles remaining.

Filled at a truck stop for $2.79/gallon and it took 2.8 gallons to bring it up to full from about 9% remaining. No big deal except the truck stop is on the long-way home.

 

[TX CTD]

I could read the tank level with my OBD2 scanner on the Gen 1 diesel. I bet you can do the same on the Gen 2 cars. I haven't looked to see if I still can now that it's deleted, the DIC just says the level is OK.

 

[PanJet]

I could read the tank level with my OBD2 scanner on the Gen 1 diesel. I bet you can do the same on the Gen 2 cars. I haven't looked to see if I still can now that it's deleted, the DIC just says the level is OK.

Gen 1 here.

It's been a long time since I've looked at it, but if I recall correctly on my Scangauge, the DEF level always read 100% until it reached 35%, then started dropping.

Aside from smaller reservoir (Gen 1 = 4.5 gallons vs. 3.8 for Gen 2), I would not be surprised if GM turned up the injection rate on Gen 2 to further suppress NOX emissions especially given the VW trouble and more scrutiny on staying within limits.

 

[jrb3]

I put about 2.3 gallons in this weekend (DIC said 34%, iirc). At 4500 miles. I know it was full from the dealership, because I watched them dump some down the side of my car when they were filling it up when I was finally taking delivery.

 

[IndyDiesel]

I would say panjet is correct, I use very little def fluid on a gen 1 diesel.

 

[NoDanaOnlyZool]

I did my first DEF tank fill-up today on my 2017 Cruze TD. I have been checking the DEF Level DIC message since about 3000 miles, and saw today that I had 37% remaining at 3228 miles. Since I was driving to a Chevy-Cadillac Dealership for work (as a Cadillac Product Trainer), and I had just over half a tank of Diesel fuel remaining, I figured I'd just buy DEF at the dealership. When I arrived for work, I was at 36% DEF Level and at 3315 miles. I bought a 2.5 Gallon jug of DEF for $16.79 including tax. That was a discounted price, too. Clearly I can save quite a bit by purchasing DEF at a Truck Stop or some other place that does not charge $6.72/Gallon for the stuff. However, since I do what I do for a living, I'll chalk this one up as a learning experience (and a $ win for the dealership team). I help them, and I try to support them whenever I can. That said, their DEF was quite pricey compared to most local truck stops which charge more like $2.80 - $3.00 a gallon. Additionally, I had about a quart remaining when I had filled my car's DEF tank. So next time, I'll probably wait until I refuel the car to top off my DEF tank as well for a lot less per gallon. Though I must add: even at the (much) higher price, DEF only cost me about half a penny per mile thus far. Quite reasonable, in my opinion. DEF and Diesel Fuel costs so far have averaged 4.98 US cents per mile.

 

[Cruze5pmOT]

I haven't had to refill in a while and it's worrying me. About 10000 miles ago. Dealer filled it (I know because they left a mess) and car readout still says DEF LEVEL OK. I stuck a clean dowel in the tank and it's 3/4 " up from the bottom . Am I panicking for no reason?