DEF usage

Jetta_Pilot

Top Post Dawg
Joined
Apr 14, 2005
Location
West Hill, Ont.
TDI
2015 Passat Highline TDI Candy White (SEL Premium) long gone 2002 Jetta TDI
I bought my car May 31st-2016. I have religiously kept track of my DEF usage. A year after I got the car I had Phase 1, the software fix done on my car.


Def usage from June 1st 2016 to June 19-2017 is:
1,638 km/liter or 1017 miles/liter


My usage after the software fix in June 2017 to today:
1,335 km/liter or 829 miles/liter


I also need to add that I was in Mexico from beginning of November until the last week of April. Mexico does not have ULSD yet so I forced REGEN's quite often to try and burn the crap out of the system. I think also that the computer causes more DEF to be used in this case.
 

goodmonkey

Veteran Member
Joined
Mar 20, 2006
Location
Anchorage, AK
TDI
2014 Passat TDI, 2011 Touareg TDI
So from that it appears the DEF usage doesn't increase substantially from the fix, 20% or so, at least on your car. Good info to know. I have no data on the Gen2 CR. Thanks for sharing.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
huh, you know what- I haven't filled mine since before my last oil change, so 15k now :confused:
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
We lasted 15-16K on the dealer fill on our NOS '15 we bought new May '17. I'm thinking the 2.5 gallons I added will last until 23k-25k miles at that point another 2.5 gallon will be added.
 

Jetta_Pilot

Top Post Dawg
Joined
Apr 14, 2005
Location
West Hill, Ont.
TDI
2015 Passat Highline TDI Candy White (SEL Premium) long gone 2002 Jetta TDI
My last DEF fill before I did it yesterday was about 10,000 miles (16,000km) ago and it took 1.6 US gal or 6 liters, but note the LSD fuel (Not USLD) usage I had while in Mexico.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
NOx output will determine DEF usage, not sulfur level of fuel.

Sulfur of the fuel will ash load the DPF sooner causing more regens but may not increase the consumption of DEF
 

sands80

Veteran Member
Joined
Nov 6, 2014
Location
Michigan
TDI
2015 Golf TDI 6MT SEL
I'm still running pre-diesel gate software- apparently at the last service interval the dealership topped off the DEF. The warning light to fill the DEF just came on. The car went about 24,000 miles between DEF fills.
 

BroncoAZ

Veteran Member
Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
I have concerns about the shelf life of the DEF sitting in my car. Living in AZ my car is cumulatively subjected to months of 100+ degree days each summer.

https://www.cumminsfiltration.com/sites/default/files/MB10033.pdf
Q. What is the shelf life of DEF?
A. The shelf life of DEF is a function of ambient storage temperature. DEF will degrade over time depending on temperature and exposure to sun light. Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures. If stored between 10 and 90 deg F, shelf life will easily be one year. If the maximum temperature does not exceed approximately 75 deg F for an extended period of time, the shelf life will be two years.

A. While DEF exposure to constant, high storage temperature may have some impact on shelf life, this should not concern operators. Extensive testing in very hot climates has been conducted confirming that DEF stored at a constant temperature of 95 deg F had a shelf life of over 6 months.


My dealer is filling the DEF each oil change, meaning I probably still have half a tank or more of old DEF in the tank. Since I purchased the car in November I’ve only had the 30K service done. I’m guessing the fill before that was either on the 20K service before the buyback in March 2017 or when they were doing the phase 1 fix and used car PDI in October 2017. I would rather the DEF tank had a drain to dump the old fluid (fertilize the lawn) and do a complete fresh fill once in a while. I probably shouldn’t care as all those components are warrantied, but my Touareg went through 2 DEF pumps, a DEF injector, and 2 DEF level sensors in 100K miles. It seems like these components failed shortly after I ran it to the warning, I believe the DEF crystallizes in the upper empty part of the tank and causes issues, so I advocate keeping the tank full rather than driving it to the warning.
 
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Fixmy59bug

Veteran Member
Joined
Aug 1, 2009
Location
Las Vegas, NV
TDI
2015 Passat TDI SE
Especially since the pump/heater is built into the tank on the Gen III vehicles and is not serviceable separately like the Gen II cars.

However, I will say that I have only seen one Gen III tank replaced as opposed to a "few" of the Gen II heater/pumps.

Out of curiosity, I saw in another thread you purchased your Passat in Vegas. Mind if I ask which dealership?
 

BroncoAZ

Veteran Member
Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
Mine came from the AutoNation VW store on Sahara. I found the car on Autotrader. I work as a consultant in the car business, AutoNation is one of our larger clients, so I called the GM at the dealership and told him I’d be there the next day to pick up the car. Easy deal. I ran up the next day with my trailer and got it. I stopped to see some buddies at the Ferrari store, hit up Fatburger, and hauled back to Flagstaff.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
I have concerns about the shelf life of the DEF sitting in my car. Living in AZ my car is cumulatively subjected to months of 100+ degree days each summer.

https://www.cumminsfiltration.com/sites/default/files/MB10033.pdf
Q. What is the shelf life of DEF?
A. The shelf life of DEF is a function of ambient storage temperature. DEF will degrade over time depending on temperature and exposure to sun light. Expectations for shelf life as defined by ISO Spec 22241-3 are the minimum expectations for shelf life when stored at constant temperatures. If stored between 10 and 90 deg F, shelf life will easily be one year. If the maximum temperature does not exceed approximately 75 deg F for an extended period of time, the shelf life will be two years.

A. While DEF exposure to constant, high storage temperature may have some impact on shelf life, this should not concern operators. Extensive testing in very hot climates has been conducted confirming that DEF stored at a constant temperature of 95 deg F had a shelf life of over 6 months.


My dealer is filling the DEF each oil change, meaning I probably still have half a tank or more of old DEF in the tank. Since I purchased the car in November I’ve only had the 30K service done. I’m guessing the fill before that was either on the 20K service before the buyback in March 2017 or when they were doing the phase 1 fix and used car PDI in October 2017. I would rather the DEF tank had a drain to dump the old fluid (fertilize the lawn) and do a complete fresh fill once in a while. I probably shouldn’t care as all those components are warrantied, but my Touareg went through 2 DEF pumps, a DEF injector, and 2 DEF level sensors in 100K miles. It seems like these components failed shortly after I ran it to the warning, I believe the DEF crystallizes in the upper empty part of the tank and causes issues, so I advocate keeping the tank full rather than driving it to the warning.

If fresh DEF is kept adding to old, you're probably got nothing to worry about.

I'd be more worried how old that DEF the dealer buys in bulk is, 2.5gal cubes are so cheap and "fresh".
 

Jetta_Pilot

Top Post Dawg
Joined
Apr 14, 2005
Location
West Hill, Ont.
TDI
2015 Passat Highline TDI Candy White (SEL Premium) long gone 2002 Jetta TDI
There must be some great differences between US VW and Canadian VW dealers or VW USA.
I hear you guys saying 2 year bumper to bumper. Not in Canada.
You take the car to the dealer and they add DEF. For FREE???? Not in Canada anyway.
 

crazyrunner33

Veteran Member
Joined
Jul 11, 2006
Location
NC
TDI
'10 Golf(bought back)
As previously noted, def usage is determined by NOx output(assuming there is no cheating). If DEF usage hasn't increased much since the fix, then EGR is used more and or timing is reduced. We see this as the case a lot on Tier 4 final heavy equipment. In the same equipment of the same year, the Perkins fills the DPF every thousand or two thousand hours, whereas the EGR free Cummins engines hardly ever see DPF issues. At the same time the Perkins sips on urea, but the Cummins drinks it like I drink my whiskey.

As for the dealerships offering free DEF top offs, it isn't free. Everything is always bundled into something else if it isn't listed.
 

BroncoAZ

Veteran Member
Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
There must be some great differences between US VW and Canadian VW dealers or VW USA.
I hear you guys saying 2 year bumper to bumper. Not in Canada.
You take the car to the dealer and they add DEF. For FREE???? Not in Canada anyway.
No, the DEF isn’t free nor are any services, but the car has a 2 year unlimited mileage bumper to bumper warranty in addition to the 11 year 162K dieselgate warranty.
 

Fixmy59bug

Veteran Member
Joined
Aug 1, 2009
Location
Las Vegas, NV
TDI
2015 Passat TDI SE
I'd be more worried how old that DEF the dealer buys in bulk is, 2.5gal cubes are so cheap and "fresh".
There's nothing to worry about here either....

We have atleast 1-2 monthly turns on our DEF inventory. So we are never sitting on a bottle longer than 6 weeks. Plus, it is in a climate controlled environment. It sees harsher temperatures sitting in the car than it does in our parts departments.

but the car has a 2 year unlimited mileage bumper to bumper warranty in addition to the 11 year 162K dieselgate warranty.
I keep seeing references to the "unlimited CPO bumper to bumper" warranty. Where does this come from?? In my car purchase packet, it says it is 2 years or 24,000 miles. And even my service advisor says my CPO certification does have a mileage expiration.
 

BroncoAZ

Veteran Member
Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
There's nothing to worry about here either....

We have atleast 1-2 monthly turns on our DEF inventory. So we are never sitting on a bottle longer than 6 weeks. Plus, it is in a climate controlled environment. It sees harsher temperatures sitting in the car than it does in our parts departments.



I keep seeing references to the "unlimited CPO bumper to bumper" warranty. Where does this come from?? In my car purchase packet, it says it is 2 years or 24,000 miles. And even my service advisor says my CPO certification does have a mileage expiration.
I’m not at home to get you a copy of the paperwork, but VW sent me a letter is late January 2018 stating my warranty had been extended. Pull the warranty coverage document by your vin and you should see all the coverages.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
There's nothing to worry about here either....

We have atleast 1-2 monthly turns on our DEF inventory. So we are never sitting on a bottle longer than 6 weeks. Plus, it is in a climate controlled environment. It sees harsher temperatures sitting in the car than it does in our parts departments.
I was just guessing if the more scrupulous places that may buy the palate size 275 gallon cubes to save a few bucks, similar to them buying bulk oil in 55 gallon drums.
 

BJS02

Well-known member
Joined
Aug 12, 2013
Location
Florida
TDI
'15 Passat SE 6MT
10k miles consumed approx 2.5 gallons of DEF Phase 1 '15 SE 6MT



topped it off @ 30k with the oil change and filled to the same point on the neck when I filled this time.
 

740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
TDI
2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Necro bump:

Got the 1500 low def warning with 26K, so that's about 10K on 2.5 gal plus one Kruss Bottle. This is phase 1 "fixed" with tune.

I did fill up two 2.5 gal jugs for $15.47 at the local truck stop. I'll prob add the other 2.5 gal at the 30k oil change.
 

phreaddy

Veteran Member
Joined
Jul 31, 2009
Location
Houston, TX
TDI
2015 Golf hatchback (purchased used in December 2021 to replace the 2015 Sportwagen (purchased new in Sept. 2017) that I totalled. :( Former TDIs: 2006 Jetta sedan (FLOODED -- Thanks, Hurricane Harvey); 2009 JSW (FLOODED-- thanks, Hurricane Harvey!)
DEF usage, heat and age

I bought my brand-new 2015 GSW in September 2017 (with 50 miles on the odo). I'm at about 11,500 miles now and just got the 1,500 mile DEF warning.

If hot weather can cut the DEF shelf life to six months, I am thinking that I shouldn't fill the tank more than about half way, since I live in southern Texas, and it took 13 months to deplete the tank this much.

Of course, the DEF that's in there now is now three years old and has been through three Texas summers.

What do y'all think?
 

KITEWAGON

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Joined
Jun 29, 2009
Location
Seacoast, NH
TDI
2014 Touareg Exec, 2014 JSW
Wow, I haven't been tracking our miles per gallons of DEF, but I think our Touareg drinks DEF compared to the smaller 2.0L engines. I feel like its more like 5k miles per 2 gallons or so.
 

phreaddy

Veteran Member
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Jul 31, 2009
Location
Houston, TX
TDI
2015 Golf hatchback (purchased used in December 2021 to replace the 2015 Sportwagen (purchased new in Sept. 2017) that I totalled. :( Former TDIs: 2006 Jetta sedan (FLOODED -- Thanks, Hurricane Harvey); 2009 JSW (FLOODED-- thanks, Hurricane Harvey!)
What does the warranty have to do with it? It's just a consumable.

Sent from my ONEPLUS A5000 using Tapatalk
 

Fixmy59bug

Veteran Member
Joined
Aug 1, 2009
Location
Las Vegas, NV
TDI
2015 Passat TDI SE
I think you got lost somewhere in the conversation....

I asked (back in June) Bronco where he saw the CPO warranty was 2 years / unlimited miles.

Bronco replied he would get get me a copy of his paperwork...

06Bluebeetle posted a copy of that paperwork today.

That is what you are seeing. It was a side conversation.

Thank you for that 06BlueBeetle. When I posted that question, all of my CPO paperwork showed 2 years / 24,000 miles. Now I have something that I can print out and keep in my glovebox should that fight come up...
 
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740GLE

Top Post Dawg
Joined
Aug 19, 2009
Location
NH
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2015 Passat SEL, 2017 Alltrack SE; BB 2010 Sedan Man; 2012 Passat,
Wow, I haven't been tracking our miles per gallons of DEF, but I think our Touareg drinks DEF compared to the smaller 2.0L engines. I feel like its more like 5k miles per 2 gallons or so.
From what I've read it's more def per gallon of fuel than def per mile (I guess they are directly related). Something like Def consumption should be 1% of fuel usage, but I guess it's all relative.

So a Passat gets 45 mpg, over 10K miles it'll burn 222 gallons of D2, 1% of that is around 2.2 gall of def, seems about true for us.

A Treg gets what avg 28mpg? over 10K that's 357 gal of D2, so that's 3.5 gal of def, so that's a 2.5 gal jug every 7K. As the MPG drops Def goes up.
 

jrm

Veteran Member
Joined
Jul 24, 2013
Location
Oregon
TDI
2013 Passat SE with nav (totaled)
yup, my friends new 2018 ram blows threw 2.5 gallon jug of def in under 1000 miles when pulling his trailer at 8mpg, also the higher the EGT's are the more it will use
 

BroncoAZ

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Joined
Apr 25, 2009
Location
Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
I have a DEF light this morning, 600 miles until the car won’t start. The dealership charged me for DEF at my 40K service, now at 45,435 miles it’s telling me to fill it?! I’m thinking either the dealer didn’t fill it or the level sensor is going bad (happened twice on my 2011 Touareg), I doubt it burned through 5 gallons in 5,400 miles.
 

BroncoAZ

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Joined
Apr 25, 2009
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Flagstaff, AZ
TDI
2015 Touareg Lux, 2015 Passat 6MT, 2009 Jetta (long gone), 2011 Touareg (bought back 02/18)
I found code P20E8 and a bunch of DEF leaking into the engine compartment.
 

showdown 42

Veteran Member
Joined
Feb 16, 2012
Location
naples,FL
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2016 TDI touareg
I just drove a 2016 with 5000 miles 3000 miles since the fluid was added,no signs yet of DEF light. My last TREG would go 10,000 miles without an alert,so I will be interesting to see if this one is different.
 
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