edsea

I have a fantastic 2016 Q5 TDI. Unfortunately it includes an AdBlu system probably required by my California CARB and dictated to the US EPA. I have been using this forum and my Audi dealer to try and learn more about this system. Some of the info seems not available, possibly as an owner I do not have the correct security clearance to know all. Here are some things I learned (or think I learned) from various sources. Can you please correct or add to this list. I do not want any trade secrets, just want to optimize my usage of my Q5.1) I read somewhere that my AdBlu tank holds about 6 gallons, true? Can’t find this info in my Q5 documentation.2) There is no way for me to know what the current level of AdBlu is in my tank in my car. My only indication is when I get a warning that I can only drive about 1500 or 1600 miles on the remaining AdBlu.3) I don’t know what level the tank is at when I get this warning. I have not collected the data to determine my AdBlu usage per miles driven. I guess that would be a good thing to do. Audi dealer cannot give me this info, said it is not available.4) I have learned that I have to add at least one gallon of AdBlu to remove the warning, the system does not recognize adding ½ gallon. That is OK with me.5) I would like to fill or almost fill the tank prior to a long trip (across country etc.). But that is difficult to do unless I fill to the overflow point. That may not be wise as I don’t know how corrosive this fluid is to have on components outside the tank. 6) My dealer supposedly just filled my AdBlu tank at my 15000 mile service. I had just added a gallon per a warning a few hundred miles prior to this service. I was interested in how much they had to add to fill it (using whatever secret indication they use to know it is full). Neither the dealer service advisor nor the service receipts could provide this information. It seemed to be lost and unavailable.I know I am pushing this issue beyond reason at least a little. And I am old school as I would like a physical way to know the level of the oil in my engine without relying on the on-board computer. I even searched for a dipstick prior to reading the manual and finding out I didn’t have one. But I do feel that more info should be provided on these AdBlu systems that we purchased and continue to contribute to. Ed

edsea

Oops, sorry but I somehow lost the list formatting when I posted this thread. Ed

MurrayA4

edsea my experience has been that I add 2.5 gallons at oil change time - 10k miles. I've never had the warning.My driving is probably 80% hwy.so I'm sure that impacts DEF consumption.I agree that there should be a way of determining level and the capacity should be given in the manual.I occasionally use a Dodge 2500 with a Cummins and you can call up the DEF level on the driver info screen.

AudioBear

For sure they can't install a dipstick in a caustic fluid so having that Dodge system would be really nice. We drove to Alaska and back last summer in our MB Sprinter based RV and I would have loved to know how much DEF I had in the tank because service stations are few and far between in the Yukon. The solution was carrying a 2.5 gallon box of DEF which added weight and took space. A Freightliner service center in Anchorage topped us off for free when we were having a recall performed. I thanked him and he said up here you need to make sure you don't run out of DEF. Wouldn't it have been nice to have a AdBlue gauge?

edsea

Well they also didn't install a dipstick on the non-caustic engine oil. I guess dipsticks have gone the path of buggy whips. Long trips in remote areas are what motivated me to start this thread. I believe it is not acceptable for an owner to not be able to determine the level of the fluid in the DEF tank, especially when the owner is responsible for managing the level in order for the engine to run. I think it is all about Audi/VW wanting minimal data available to all on this topic. We spent 60 days in the Yukon and Alaska with my 2010 Dodge Cummins, no AdBlu system which was nice. Possibly if I decide to get the emissions fix installed I will have to figure out how to install the factory hitch and tow a small AdBlu tank, Audi should love that if it is properly labeled. Ed

arter

The listed DEF tank capacity is 24 liters or roughly 6 gallons.

Theoretical DEF usage rate is 1 gallon of DEF per 50 gallons of fuel.
So if you get 25 mpg you would get 1250 miles per DEF gallon or 7500 miles per a full fill with standard DEF usage rates ( not Audi rates)..

Now with the tampered software, our Q5's dont use DEF currently at that high of a rate, probably half that rate ( or less).
With the new software if should rise to the standard rate ( which is why they know they can not go 10000 miles between DEF fillups.)

Bob Petruska

VCDS will show the tank level as a percentage.
in Engine -> Advanced Measuring Values -> 98-0:Sensor

Now some say if the tank is 1/3 full it will register 100% on VCDS, others say that their tank only registers 100% when full.

This is what the dealer uses and it won't overflow............

edsea

Thanks Bob, more complex than I realized. For both long trips and at home for me (I have a 5 hour roundtrip to the nearest dealer), dealing with this without dealer assistance is required. Thks again, Ed

DennisMitchell

This link has some background and advice on AdBlue servicing.

Adblue with DPF FAQ: pictures, cleaning, and repair | VW TDI forum, Audi, Porsche, and Chevy Cruze diesel forum

edsea

Thks Bob and Dennis for providing lots of real info on these emissions systems. Wow they are complex, way too complex. Considering all of this engineering and development that went into these cars and then was all blown away by diesel-gate is very sad or very maddening depending on your point of view. As much as I love diesel technology (I have 7 diesels in cars, trucks, boats, and tractors) I have to wonder if the complexity with current emission requirements is really worth it—maybe pain is exceeding gain. Especially with the latest gas technology available.

I do not have a VCDS tool, and it seems that may be a path to knowing how much DEF I have in my tank. I heard about the VCDS (I believe it is just a cable and software to use with my laptop) but decided I don’t do enough maintenance myself to justify it. I used to do everything including engine rebuilds but now I don’t even change my own oil. However the DEF level capability might justify it, but even that seems to be questioned as to what it really indicates as mentioned in the thread.
.
While I find this info very helpful (thanks again) I also find it kind of scary. Lots of room for failures and weird symptoms in my view. The turbo diesel forum link is very detailed but doesn’t list Q5 specifically possibly the Q7 is close enough but lots of difference in size/room for these many components so they may be quite different. I am beginning to understand why VW is questioning the wisdom of diesels in the US. However I also question if all of these new gasoline solutions are any cleaner than our TDI’s are. The People’s Republic of California seems to be focused on killing off diesels so maybe the gas vehicles get a break.

I am still looking for a simple way to know how much AdBlu I can add to my tank so I can keep it closer to full rather than dealing with the 1500 mile warnings. Ed