[TDILow3]

What is the official guidance/policy from VW regarding the use of fuel additives with a Diesel Particulate Filter (DPF) equipped TDI? I ask because VW was "so specific" regarding the 507.00 engine oil to protect the emissions system (and that oil is not a normally stocked item at the local parts store), that it is only logical to assume that VW has some specific guidance/policy/standard regarding the use of cetane boost and injector lubricant additives to protect the DPF, oxidation bed...

Recently replaced my 2003 Jetta TDI with a 2011 Jetta Sportwagen TDI, which is fundamentally different than my earlier TDI: injector type, emission system components...

 

[NJ2dc]

Although I wouldn't accept an answer on an online forum if your car's warranty relied on it, I've heard VW is saying Standyne is OK. But don't rely on what they or dealers say unless you get it IN WRITING. Refer to your owner's manual or call VW customer care for documentation.

 

[Marc_TDI]

I wouldn't take the Dealers word as it varies depending on which dealer and also who within that Dealership you might talk to - some dealerships actually sell Standyne - so as you can see their
say-so is not constant.

Get it in writing - which they won't do.
VWoA - on the phone will tell you "not to use" but won't put it in writing.

I believe the manual states additives aren't needed - I don't believe it states you shouldn't use one, I will re-read my manual again to be sure.
This however doesn't take into account our diesel fuel in the USA which lacks the lubricity found in European diesel fuel, which these engines were designed to run on and require.
From there the debate ensues - it's long and opinionated with many on both sides of the "to use" or
"not to use" camps. There's no scientific means to show if it really works - with the small exception of The Spicer Report.
This is not that relevant as it was done with untreated/raw diesel fuel and the oil companies have additive packages they use and won't divulge the contents therein.

I've read that the use of an additive in our TDI's ranges from "snake oil" to added insurance and peace-of-mind.

Too much lubricity compounds could possibly hurt the DPF (Diesel Particulate Filter) and since we don't know the make-up of various oil companies additive packages - is using an additive "too much".
You will find this in the debates when you start reading them.
The thing is we don't know because there isn't enough history built up with the CR engine
in the 2009/2010/2011's to see patterns in problems with the lack of lubricity.

I would say read through as much as you care to, then make up your own mind whether "not to use" or "to use" and then which brand. I would caution not to tell the dealer you are using an additive as they have on occasion used it as a means to void the warranty - which is total nonsense!
One Dealership has employed the laughable "Styrofoam Cup Test: wherein they pour diesel fuel in a Styrofoam cup and it dissolves the cup - this is their proof you use an additive - funny thing is diesel fuel with no additive also dissolves the cup.

I started using Opti-lube XPD at around 5K on my 2010 TDI Jetta, I did notice an immediate quieting
at starting and running of the engine and it appeared to run smoother, but this not scientific.

I hope this somehow helps or directs you - I'm not trying to start up the debate here - just relay what I have read on Forums regarding additives.

 

[TDILow3]

Roger on all. I have been a shipboard diesel mech for 20+ years, but you don't find diesel particulate filter systems, oxidation beds...on these applications (at least not yet), which is why I am looking for a standard. As for the consistency of diesel fuel, at least at the shipyard bunker level, diesel fuel is not a grade of fuel, rather it is a 'range of fuel' that sees some very large variations and yet it still carries the same label. I find it hard to believe that the 507.00 engine oil standard could be so tight you can't find it on the shelf at the average retailer, but you can tank up with just any old ULSD that comes out of the pump, which changes drastically from supplier to supplier. With my 2003 TDI there were some measurable tank to tank MPG differences, which over time I figured out what stations were providing diesel with high cetane values and high energy density values. An indirect method, but I knew what stations were selling the 50+ MPG distillate and what stations were selling the less than 45 MPG blend.

I do find a little solace in explicit comments on the Diesel Kleen bottle that states it is compatible with 2007 and later diesels equipped with a diesel particulate filter and that it won't void the OEM warranty. That tells me that they are making a conscious decision to update/control their formulas to prevent binding compounds to the emission beds/substrate/media and are trying to work in concert with the emissions systems. As for finding solace with VW, they just need to provide acceptable limits, like a MIL-PRF, that will provide the aftermarket manufacturer's with a target.

As a general rule, you can't go wrong with lowering the HFRR value of the fuel and all performance diesels are noticeably impacted by low cetane values. However, outside the combustion chamber the compounds used to lower the HFRR and raise the cetane may harm the emission systems. With a modern 'emission equipped' diesel I would never add motor oil or 2-stroke oil to my diesel fuel. However, for the aftermarket fuel additives that have not updated their labels since 2007 to formally recognize that a change occurred...they may be running the same 'pre-emission system' blends, which have the potential for causing havoc between the exhaust valve and the tail pipe.

As for the Styrofoam cup trick, I would eat them alive as my background/education is in material science, mechanical engineering, and manufacturing. The Styrofoam test is nothing more than a "solvency test." Jumping over into real engineering, it would be similar to ASTM D4752 solvent sensitivity testing. You can break down the Styrofoam cup with any short chain aromatic hydrocarbon because it is a thermoplastic (reversible reaction) not a thermoset (permanent cross-linked reaction).

If any solid guidance/bulletins hits the streets, please send it my way.

 

[Plus 3 Golfer]

Although the owner's manual is silent on using additives in the CR TDI, VWoA has many times put their "official" policy on using additives in writing.

I emailed a question to VW Customer Care centered around two Stanadyne products - ZVW340001 and 0002 and whether these products or any products were approved or recommended for use in the common rail TDI. I indicated in my question that there seems to be confusion among dealers and customers since these products have VW part numbers and dealers are selling these products for use in the CR engine.

My response from CC (below) was consistent with responses received by others who emailed VW CC asking about additives in CR TDIs - VW does not recommend using additives in the CR TDI.

Thank you for your e-mail to my associate, Jamie, sharing your questions regarding fuel additives in the fuel for your 2009 Jetta TDI. I understand you’re seeking to know if there are any approved and recommended additives for the fuel in our newest TDI vehicles, and I appreciate the chance to answer your question.

Please know I have researched your question. In our older TDI vehicles, cold weather would, at times, make it more difficult to start our diesel-powered engines. There was a small number of approved diesel additives to help promote a cold-weather start. With our new clean-diesel TDI engines, beginning with our 2009 model year vehicles, advances in diesel technology have made cold-weather starting very easy in all but the most frigid areas of the world. For this reason, we currently do not recommended additives in the fuel for your Jetta TDI. I hope this helps to answer your questions, and I thank you again for taking the time to contact us.

 

[Keithuk]

VW say "The latest generation of filters operate without additives." Diesel Particulate Filter

 

[TDILow3]

Thanks for the VW Customer Care quote. They clearly took the "specifically vague" approach, not recommending the use of additives nor discouraging/restricting their use. Nor did they touch on the lubricity concerns with ULSD or the variance in diesel fuel in general.

I wonder if framing a more pointed question, directed at the diesel particulate filter, would prompt a difference response? Can you provide the contact information for VWoa Customer Care (email, website...) such that I can initiate a pointed DPF question regarding additives?

 

[TDILow3]

I believe the context of that article was directed towards the "urea injection" diesel exhaust emission systems that inject additives into the exhaust system to reduce the NOX emissions, which the VW clean diesel does not employ.

 

[Plus 3 Golfer]

Thanks for the VW Customer Care quote. They clearly took the "specifically vague" approach, not recommending the use of additives nor discouraging/restricting their use. Nor did they touch on the lubricity concerns with ULSD or the variance in diesel fuel in general.

I wonder if framing a more pointed question, directed at the diesel particulate filter, would prompt a difference response? Can you provide the contact information for VWoa Customer Care (email, website...) such that I can initiate a pointed DPF question regarding additives?

Go to the VW website and find the "contact info". You give your VIN and then can submit your question. There is no email address for VW CC.

I doubt you will get a different response from VW as they do not recommend that the consumer use additives to the fuel be it for cetane, lubricity, DPF, or any of the catalytic converters. But go ahead and submit a more detailed question. I know others have specifically asked about additives for lubricity and got a similar response. I sent that question in specifically asking about Stanadyne because there were dealers and forum members adamantly stating that VW endorses the use of Stanadyne in the CR TDI.

IMHO, VW will not issue general recommendations on additives to improve fuel quality like cetane, lubricity and so forth. If they issue any recommendations it will be with specificity i.e., use this specific additive X for this specific condition Y as they have done in the past for diesel engines. To issue general recommendations would undermine their products: VW selling TDIs that potentially fail on ULSD or marketers selling ULSD that cause potential failures of TDIs. Like VW, you will find Chevron and the likes not recommending additives: "In General, Chevron does not recommend adding after-market additives to diesel fuel". Their lawyers (VW and marketers) simply aren't going to let them recommend anything without specificity (again, this product for this specific condition).

However, VW's silence on additives or statements from Customer Care about not recommending additives does not mean that additives will harm components. I have weighed the cost/benefit of using additives and have concluded that using 2% biodiesel + PS DieselKleen is sound risk management for my CR TDI.

 

[TDILow3]

Agree with and your logic is sound with regards to the OEM (lawyer) stance. There is the right thing to do and the legal thing to do.

I don't think that VW designed a TDI that will fail on ULSD, but I know that diesel fuel varies wildly from source to source. Shipboard diesel fuel is randomly sampled and sent out for laboratory analysis, and we get the results 'well after' we have already burned the diesel. I have seen API gravities upwards of 40 (the kerosene range) and down to 28 (diesel with a good energy density). Indirectly we can tell gage if we had a low or high API fuel by the fuel consumption rates of our diesel generators at a given KW load. When the API was near 40 we would observe upwards of a 5 to 10% increase in the gallons/hour consumption rates, as compared to a below 30 API diesel. (Some OEM diesels have charts to correct the 'maximum HP' of their diesel based on API gravities) I have even seen laboratory test results of the diesel we already burned with a flash point well below 100 deg F and a very high API gravity, suggesting that the diesel had some very short chain hydrocarbons (gasoline) in the mix. I believe this was the result of carriers using 'non-dedicated' tanks and moderate to significant amounts of other fuel grades left/remaining in the tank when the diesel was loaded. I don't see why the common everyday 'gravity fed' delivery truck you see at the fuel stations delivering fuel would not use the same tank re-appropriation methods to size the load(s) that they are delivering that day - effectively cutting the ULSD with other grades of fuel. Next time you see the gravity fed delivery truck at the local fuel station take note of the "flip wheels" right above the cam-lock hook ups, you will see that they can be rotated to show what fuel is 'currently' in that tank and it can be rapidly changed at will when the liquid cargo in that tank changes.

I decided to approach Diesel Kleen directly, as they are the only additive company that I see 'addressing' the DPF and 2007+ emission systems compatibility as part of their marketing. I have not heard back, but I was very explicit and I called attention to the VW 507.00 engine oil standard, which was so strict that the average auto parts store doesn't stock the oil. If I receive a response from Diesel Kleen, I will post it on this thread.

***BREAK, BREAK, TOPIC SHIFT***
I am very much about data and statistical analysis of systems. Is there any hard data or trend analysis regarding the use of cetane boost and lubricity additives and the lifespan of a DPF? The technology appears to be rather new, at least to the mass production theater, so there may not be enough data to prevent extrapolation.

Looking at the commercial diesel truck theater, I noticed that there is a DPF "cleaning infrastructure", with some OEM trucks outfitted with factory DPFs that are "built-for-maintenance." By built-for-maintenance I mean that some DPF filters are intentionally moved away from the engine exhaust valve, giving up the high temperature opportunity for active regeneration, in lieu of an easily removed DPF cartridge/canister location. These cartridge/canister style DPFs can then be run thru a DPF re-generator or swapped for an on-the-shelf overhauled/regenerated DPF cartridge.

As time elapses and the miles amass on the TDI DPF system, we may start to see the same DPF re-generation infrastructure emerge form for the private diesel engine market. At that point, we may start to get some good data as to what the 'typical' cetane/lubricity additive DPF looks like and what the non-additive DPF looks like.

Your thoughts?