Juicy tidbit for you VW diesel engine owners

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Jun 2, 2003
I recently came on some Euro website (I think it was a SEAT site) across the information that no matter whether or not a VW diesel engine is equipped for Long Life Service, an oil change is required every 7500 km (ca 5k mi), if diesel fuel with higher than Euro standard sulfur content is used. I don't know how much sulfur is allowed in Western Europe, but chances are that the diesel fuel in many countries does not meet the requirements. This may well affect those of you in the US who own VW diesel engines, and you may want to take this info under consideration when planning your oil change intervals.
with all due respect, I would assume that the oil change intervals for US VW engines take into consideration the sulfur levels of the fuels we have here. Therefore I don't believe that shorter intervals are required. But, thanks for the "heads-up", all information is appreciated. I routinely went 10-12,000 miles on my 2002 Tdi using Delvac 1 and the oil anaysis at each change came back as showing the oil had a long way to go before being compromised by soot or degadation.
"With all due respect," but by your own words, you are just "assuming" while placing unwarranted faith in VoA. Going by your assumption I must assume that the sulfur limit in US diesel is the same as in Euro diesel fuel. Alas, I don't assume, especially when I know that assumption to be incorrect. I was talking about sulfur content, you talk about your UOA. I don't know if the sulfur content leads to a corrosion issue or if it's about something else. While your UOA may be fine, this may be about an issue not addressed by UOA. Anyway, what's with the attitude? I didn't tell you to do anything. I could care less what you do. I was simply mentioning information I found. I was hoping interested parties would pick up that info and see if it were to apply to their diesel. "With all due respect," I'm not gonna do their homework for them. [Razz]
Now boys [No no] play nice. The diesel fuel in the USA is no where near as good as the diesel fuel in Europe. It will be sometime near the end of 2006 or 2007 before it is. Way to much sulphur in our diesel.
The diesel fuel in the USA is no where near as good as the diesel fuel in Europe.
That's why I posted that information.
Now boys [No no] play nice.
Or else the girls will start crying? [Razz]
I just got a hold of these comments regarding high sulfur fuel by Doug Hillary. I expect his thoughts on the issue will be taken into consideration.
High sulphur (HS) fuel (above 0.3%) significantly increases ring face wear rates The following sulpfur level table (TSE279/99) may interest you; 0.1% = 100% of relative engine life is possible, then; 0.3% = 90% 0.5% = 40% 0.7% = 20% 0.9% = 10% 1.1% = 10% 1.3% = 10% 1.5% = 10% of relative engine life may be attained Idling and low operating temperatures (ambient/engine) are the main components combining to form destructive acids with HS fuel. Until 2000 Australia had very HS fuel levels - these caused enormous premature wear issues in some engines, both petrol and diesel It is one reason why I deviate very little from Approved & Listed oils now At HS levels oil drains must be shortened (it is OK to monitor TBN/TAN via UOAs like I did) with the original TBN's reduction to 1/3 being the OC trigger Using a high starting TBN oil with longer OCIs is NOT as effective as using UOAs to determine acid level protection and moderating the OCI as needed Sulfated ash levels are related to the oils TBN and its additive package. As the TBN increases sulfated ash levels increase too. An oil with a TBN of say 10 and an ash level of 1.2% is less desirable than an oil with the same TBN and ash level of 1%
It sounds to me like sulfur content in the fuel directly affects oil condition, and a shortened OCI, on which I had orginally touched, may well be warranted.
I think the sulfur content in German diesel must be <0.05%. Shell claims their "Dieselshell" has <0,035%. The sulfur content varies around Europe. Modern Danish truck diesel has 0.00001%, hence considered sulfur-free. Aren't we sacrificing the lubricity with these ultra low S-levels?
I don't thing the high sulfur issue in the US affects engine longevity. There are plenty of threads on tdiclub with folks achieving 300k on 10,000 OCIs. I'll stick to the 10k OCI but I do appreciate the info you provided.
Oh, it seems my math is wrong, thank you tdimaniac! The Danish truck diesel i mentioned contains 10 ppm sulfur => 0.001%. I believe we are fine with the road diesel in The States and Europe. The agricultural diesel here in Germany is the same as the road diesel, so our tractors do not need to bother with bad food!
no problem, it was getting a little confusing with everyone posting various "ppm's" & "percents". bottom line is that according to the way i interpret this info, 10,000 mile oci's are fine for tdi's in the states (despite our rot gut diesel supply). it is the job of the tbn to neutralize any sulfur based acidic compounds anyways.
UK diesel has been below 50ppm (0.05%) for a while: fuel companies were given an incentive to bring in virtually zero-sulphur before the Euro Directive required it. This is mainstream diesel: there are other sources which might be doubtful, esp. with acid-treated agricultural diesel (low tax concession, dyed red, with acid used to remove the colour) being sold from retailers and ramshackle bowsers near the NI border.
current us diesel is 500 ppm sulfur (0.05%). i think this is termed "low sulfur". ulsd coming later this year is 15 ppm or 0.0015%. fyi 10% = 100,000 ppm 1% = 10,000 ppm 0.1% = 1,000 ppm 0.01% = 100 ppm 0.001% = 10 ppm as crappy as us diesel is, it is still better than 0.1% for "100% service life". thanks for the info regardless (and i am happy with 10000 mile oci's and d1 as well for our tdi). http://www.eia.doe.gov/oiaf/servicerpt/ulsd/chapter4.html
The concept of a flat 10,000 mile OCI is wrong ! While many will do well with this interval, many more simply need to change their oil a lot sooner.. Using the OA(oil analysis) as a determinate is good ; better is GM's computer controlled system, whereby all factors are taken into account. And this is very similar to that system used by the big rigs.. And this may not cost that much on a per mile basis as the TDI is driven so much...
Flat 10, 000? Thats old hat. 10,000/annual only appies in severe conditions in Europe. VW/Audi "algorithms" for easy duty, give up to 30,000 miles in engines equipped with sensors.
I currrently run 25,000 OCI's with Delvac One 5w40 aka Mobil One Truck & Suv. A 10,000 mile OCI is what VW recommends after the first 2 oil changes. (5k ea)
In Europe, its 10,000 from the start. Don't know why the US is different: maybe its the fuel? But when ULSD comes in will the US OCI change to match the arrangements over here?
lots of 10000 mile oci uoa's for north american tdi engines in the diesel uoa subforum. most of them show no problem with extended oci's. i always thought the first two 5k oci's were to flush out the manufacturing "debris" from a new engine.
Yes I've heard that story about swarf and debris too. But PD engines on both sides of the pond are from identical plants. Now unless VW have different lines, with lower tolerances for USA, I tend to the view that the dealers are best suited by unnecessary oil changes, as part of their revenue stream.
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