A response from VW AG about Biodiesel

This is an email reply sent to me back in 7/2001 (just after I decided I wanted a TDI.. got a 2002)

Dear Mr. Lynch,

Thank you for your enquiry.

We are happy to provide you with the following information:

Since model year 1996, all Volkswagen passenger vehicles with diesel engines
have been built for use with RME (Bio Diesel) complying with the norm "E DIN
51 606". Please check within your vehicle's instruction manual for
information about using Bio Diesel.

If problems with the fuel filter and injection system should occur despite
meeting the above conditions, then poor fuel quality is the cause of the
problem.

It has been shown that the quality of Bio Diesel does not always conform to
standards. We recommend that before filling up, you ask at the gas station
for confirmation of the quality (DIN- standard) of the fuel.

If your vehicle has had auxiliary heating built in, please contact the
appliance manufacturer to find out whether it is possible to use the
appliance along with Bio Diesel.

Yours sincerely,
Volkswagen Customer Relations
Angelika Rudolph

He didn't say anything about %, though...... just said it was approved....
thoughts, anyone?

RME rape seed based bio

The E din standard is a European standard, I believe.

Not likely to find rape seed based bio in N. America.

The manual says up to B5.

http://www.vw.com/contactus/faqs.html#5.1

vw does not cover any fuel related failure to it's engines.
burn b100

kpltdi said:

He didn't say anything about %, though...... just said it was approved....
thoughts, anyone?

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She didn't mention a % because at that point they hadn't yet experienced all the problems they have had since that time. They did specify rapeseed biodiesel, not the soy that is the common plant here. Rapeseed and soy biodiesel have different properties. Someone else can explain the differences (or already has- search).

VWoA has since gone to a much more conservative approach on the newer vehicles (B5 for now using soy-based biodiesel). I'm sure if you could find a biodiesel that meets the DIN standard mentioned somewhere here in N.A. they would be OK with it. Until you can do that, just understand that if you use anything higher than B5 over here, you are not going to be covered by the VW warranty. Hopefully over time we will see better regulation of biodiesel production and VW will accept higher NA produced mixtures.

FWIW, I have used B99 in both my TDI's with the only problem being some leaking around the older one's injection pump gaskets.

Note who said what. VW AG said Bio was OK.

VW of A said only up to 5%.

Since in North America we buy our VWs from VW of A that's the company that matters to us. VW AG doesn't have any problems with running bio - they're fine with it.

RAST said:

VW AG doesn't have any problems with running bio - they're fine with it.

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VWoA doesn't have engineering resources, AFAIK. All of the technical specs and engineering come from AG. The point is that the bio AG is ok with (RME) is not equivalent to the bio most of us in N.A. have access to (soy-based). So to say that they don't have any problems running bio is not really accurate.

ASTM D6751 - If your supplier meets those specs, it should satisify VW of A. I doubt anyone in the US meets DIN specs.

pat

Have you read the ASTM D6751 specs and it's title? Folks might find it enlightening.

tditom said:

VWoA doesn't have engineering resources, AFAIK. All of the technical specs and engineering come from AG. The point is that the bio AG is ok with (RME) is not equivalent to the bio most of us in N.A. have access to (soy-based). So to say that they don't have any problems running bio is not really accurate.

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Hmm, maybe I was confusing -- I thought I was clear but I guess not.

VW AG is fine with Bio that meets DIN E 51606 spec. Here's proof of that: http://forums.tdiclub.com/showthread.php?p=1305755

VW of A is only B5. I never meant to say that VW of A is Ok with bio > B5.

Dave-

You said:

VW AG doesn't have any problems with running bio - they're fine with it.

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I just tried to clarify the difference between the different types of biodiesel. I inferred that you were claiming that VWoA was restricting the use of biodiesel with no rationale. I wanted to communicate to the original poster that there are differences between biodiesels and that there is a reason that the new North American vehicles are limited by VWoA to a 5% mixture while vehicles over the pond can run up to 100% if the fuel used meets the appropriate specs. VWoA has rightfully earned a bad reputation with their "customer service", but in this situation they are being directed to limit the biodiesel to 5% by the engineers at VW AG because of the lack of standardization of biodiesel production on this continent.

I'm just trying to make sure the right info is out there and answer the O.P.'s query without any confusion.

tditom said:

She didn't mention a % because at that point they hadn't yet experienced all the problems they have had since that time. They did specify rapeseed biodiesel, not the soy that is the common plant here. Rapeseed and soy biodiesel have different properties. Someone else can explain the differences (or already has- search).

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People *really* need to stop listening to Audi5k when it comes to technical info on biodiesel. The operational properties between rapeseed and soy biodiesel are very small - the primary difference is that rapeseed has better cold weather properties (but that can be dealt with). See http://www.biofuels.fsnet.co.uk/comparison.htm
for a comparison of the properties of biodiesel from various feedstocks, and a comparison of various biodiesel specifications (ASTM, EN, DIN, etc.).

It appears far more likely that the technical writers for VW just view RME as being synonymous with biodiesel, not understanding that it can be made from different feedstocks, based on how they refer to it (i.e. RME (biodiesel)). They don't say "VW only approves of biodiesel made from rapeseed".

I'm sure if you could find a biodiesel that meets the DIN standard mentioned somewhere here in N.A. they would be OK with it.

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99% of the biodiesel that meets the ASTM spec, also meets the DIN spec. Look at the specs in comparison to each other (again, I've posted the link above many times - apparently rather than looking at the link to compare the specs, people just want to keep assuming that the DIN spec is much more strict than the ASTM spec - it's not).

Hopefully over time we will see better regulation of biodiesel production and VW will accept higher NA produced mixtures.

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Yes, that is the issue - VW is concerned about the fact that in the US, producers aren't *required* to do quality control testing to make sure their fuel meets the ASTM spec, it's strictly voluntary. It's not about the ASTM spec being deficient, or the fuel being made from something other than rapeseed - it's the lack of a *requirement* for quality control.

wny_pat said:

ASTM D6751 - If your supplier meets those specs, it should satisify VW of A. I doubt anyone in the US meets DIN specs.

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It's amazing how you guys can make claims like this. Do you even KNOW what the DIN spec says? You clearly do not, since the DIN and ASTM specs are very, very similar. Most biodiesel that meets the ASTM spec will also meet the DIN spec. Some biodiesel that meets the DIN spec won't meet the ASTM spec (i.e. ASTM is tighter on the flash point, and vice versa, due to very small differences in a few of the tests - differences way too small to make any difference.

For a strict comparison of just the ASTM and DIN specs (since apparently you guys don't want to look at the other reference I've given which compares every biodiesel spec, as well as biodiesel from different feedstocks), how about this one:
http://ms-biomass.org/conference/2003/lurgi%20psi.ppt#20
Look at the ASTM spec compared to the DIN spec and tell me what it is that's so much tighter on the DIN spec that ASTM fuel can't meet it.

ASTM is more strict on flashpoint (DIN also regulates methanol percent remaining, which ASTM doesn't (not shown in that slide), but that's a redundant test - residual methanol brings your flash point WAY down very quickly, such that you'll fail the flash point test well before you fail the residual methanol test that DIN has). DIN is slightly more strict on water and acid number, although both are easy to meet. They have the same free glycerin level, and ASTM is more strict on total glycerin (DIN regulates individual glycerides, while ASTM does not - but that's unnecessary). They have about the same cetane level, the same carbon residue level. DIN regulates cloud point, while ASTM says it should be reported to the user/retailer (the same thing as they do with the ASTM spec for diesel fuel).

So, what is it that you guys are claiming is so much more strict about the DIN spec that ASTM fuel is poor quality by comparison?

Can someone answer that, rather than just repeating this absurd claim that the biodiesel in EUrope that meets the DIN spec is so much better quality than ASTM bio?

Thanks, Mike, for clarifying the issue. (BTW I did review the specs) As I speculated earlier (here or in the other thread)- perhaps the Germans just don't have enough experience with soy based bio, so they are being ultra-conservative (at this point) and are using RME=biodiesel. But they are very explicit in the current documentation that we have seen in that they only refer to RME biodiesel. That's a fact, agreed?

Do you have any explanation for the "biodiesel modification" that is done on at least German vehicles that run B100?

tditom said:

Thanks, Mike, for clarifying the issue. (BTW I did review the specs) As I speculated earlier (here or in the other thread)- perhaps the Germans just don't have enough experience with soy based bio, so they are being ultra-conservative (at this point) and are using RME=biodiesel. But they are very explicit in the current documentation that we have seen in that they only refer to RME biodiesel. That's a fact, agreed?

Do you have any explanation for the "biodiesel modification" that is done on at least German vehicles that run B100?

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I know, it's kind of like GM saying "Corn-based E85" instead of just E85. The Europe spec is not feedstock-specific, and in fact if you compare the RME, SME and D2 you'll find RME has a higher viscosity rating but lower cloud point. So in some ways SME (Soy-based Methyl Ester) is closer to D2 than RME.

Any way, this is all pure speculation on our parts -- VW AG knows the answers. Now if we could just ask them the questions! Personally I would be more than happy to pay to retrofit my TDI with the bio package if I knew what the heck it was

tditom said:

Thanks, Mike, for clarifying the issue. (BTW I did review the specs) As I speculated earlier (here or in the other thread)- perhaps the Germans just don't have enough experience with soy based bio, so they are being ultra-conservative (at this point) and are using RME=biodiesel. But they are very explicit in the current documentation that we have seen in that they only refer to RME biodiesel. That's a fact, agreed?

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Agreed that they refer to RME as biodiesel - I still think though that the reason they do is the technical writers not being very knowledgeable about it, and thinking that all biodiesel is RME - not unlike how many journalists in the US mistakenly refer to biodiesel as "soy oil mixed with diesel".

Do you have any explanation for the "biodiesel modification" that is done on at least German vehicles that run B100?

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I wrote about that in this or another thread. My understanding is that it's a sensor that detects the amount of biodiesel and adjusts the injection timing to eliminate the slight increase in NOx emissions from the biodiesel.

Hi Everybody,

I've searched some of the German websites on info to this "problem" with biodiesel.
If I may contribute my 2 cents...
DIN E 51606 is for over one year out of commision, the E from Entwurf meant is was a preliminary standard. It was superseeded by the European standard DIN EN 14214. That's was it currently in effect. The controversy about what should/could be used in diesel engines is complicated. VW AG does warrant cars driven with biodiesel if A) the car has the official blessing, like for Golf V it requires the optional RME-kit, and B) the fuel used adheres to the DIN EN 14214 standard. The RME-kit is nothing more than special fuel lines (supposedly silicone-based) and seals, the sensor mentioned was developed about 1 year ago, but is not used yet. The problem is, Bosch, the company making the fuel pumps and apparently the PD system, does NOT warrant their parts for the fuels even if the new standards are met. It seems the droplet size of biodiesel is larger than from diesel and despite better overall lubrication it doesn't lubricate the injectors as well at these high pressures, or so the story goes. So even in Germany you can't automatically assume your covered under warranty if the injection system develops a problem.
The new standards for biodiesel in Europe do not specify RME per se, but the standard allows/requires the use of additives that stabilize the methyl esters (MEs) and almost all research has focused on RMEs in Europe. So, the formulations to stabilize the fuel etc. are based on RMEs only. Part of the story is that the composition of various MEs varies greatly, just look at the link posted (http://www.biofuels.fsnet.co.uk/comparison.htm
), bottom of the page - fatty acid copmposition.
The oxidation of the fatty acid methyl esters is different, and the current additives have been developed for RMEs. Oxidation will lead to fatty acids, combined with the higher water content of biodiesel will lead to increased corrosion, especially Zinc-based ones.
In addition, the particle filter that are more and more in use to remove soot, require the whole engine/exhaust system to be adjusted (apparently) and are currently standarized for dinodiesel. So, more and more manufactures in Europe are actually pulling their certification for biodiesel (B100) in new models or require the RME-kits.
Mixing biodiesel with regular diesel alleviates the problems associated with pure RMEs, and so in short 5% is safe to use, IMHO B20 is just fine, too.
And yes, testing in Europe IS mandatory, and should be here, too. Even the test methods used are standarized, so that everything is comparable.
Feel free to ask anything else, but I think that 2 problems in the US exist with biodiesel: lack of mandatory, standarized testing and long term experience with stability of SMEs and following corrosion/lubrication problems, especially with PD engines.
VW AG is looking into "sunfuel", which makes use of all organic waste (say the whole plant instead of the vegetable oil only) and to synthesize diesel from it. The advantage is like for synthetic motor oil, predictable stability and behavior. But that will take time.

Hope everybody sees that, somehow, everybody is right (and wrong) at the same time, and I include myself in that. The summary above is my understanding based on information found on the internet. I am a scientist, and chemistry was a hobby of mine, so I do have a certain level of knowledge, but again, some information could be on questionable ground. There you have my disclaimer. Please don't sue me.

Folks,

The mandate for B5 in the USA is not controlled by VW of America. It is mandated by Bosch, who manufactures the injection systems and warranties what they make for VW... so instead of sourcing out VW, source your information from Bosch.

For whatever reason, I'm sure it's valid, Bosch doesn't just make this stuff up or pull a number out of their ass for what blends of Rapeseed Methyl Esther or Soy Methyl Esther is acceptable in Bosch Injection equipment. I'm certain wear tests and corrosion test have been performed and the results logged and analyzed before release to the public.

NHMike, how can you possibly make such statement and override Boschs fuel recomendations for a blend of up to B5 in the USA? Put your money where your mouth is.

Here is what happens when you run B20, through heat cycles as observed in a TDI where the fuel is heated and goes back into your fuel tank. Pages 5 and 6 describe the problems with B20 and cyclical drive and shut off, drive and shut off. This is summarized test results by Bosch and based on Soy Based Methyl Esther fuel.

http://www.arb.ca.gov/fuels/diesel/092904biodsl_bosch.pdf

MouseMan said:

The controversy about what should/could be used in diesel engines is complicated. VW AG does warrant cars driven with biodiesel if A) the car has the official blessing, like for Golf V it requires the optional RME-kit, and B) the fuel used adheres to the DIN EN 14214 standard. The RME-kit is nothing more than special fuel lines (supposedly silicone-based) and seals, the sensor mentioned was developed about 1 year ago, but is not used yet.

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Ah, I was under the impression the sensor was already being used. I don't know why they would bother putting different fuel lines and seals in to make them biodiesel compatible - VW normally uses Therban, a hydrogenated nitrile rubber that is compatiblie with biodiesel.

The problem is, Bosch, the company making the fuel pumps and apparently the PD system, does NOT warrant their parts for the fuels even if the new standards are met. It seems the droplet size of biodiesel is larger than from diesel and despite better overall lubrication it doesn't lubricate the injectors as well at these high pressures, or so the story goes.

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THat doesn't make any sense (Bosch claiming it doesn't lubricate the injectors as well at high pressures).

So even in Germany you can't automatically assume your covered under warranty if the injection system develops a problem.
The new standards for biodiesel in Europe do not specify RME per se, but the standard allows/requires the use of additives that stabilize the methyl esters (MEs) and almost all research has focused on RMEs in Europe. So, the formulations to stabilize the fuel etc. are based on RMEs only.

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Methyl esters from different feedstocks aren't so different that oxidation stabilizers would work on one type of biodiesel and not another.

Part of the story is that the composition of various MEs varies greatly, just look at the link posted (http://www.biofuels.fsnet.co.uk/comparison.htm
), bottom of the page - fatty acid copmposition.

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The makeup of different oils in terms of what fatty acids they are made of does vary - but that shouldn't have any substantial bearing on the affect of oxidation stabilizers. For example - vitamin E is present in most oils to begin with, and is an excellent stabilizer to prevent oxidation of biodiesel - regardless of the fatty acid profile of the particular oil. Stabilizers prevent oxidation by essentially sacrificing themselves, to prevent the fuel from being oxidized. So, it doesn't depend on the makeup of the fuel itself. That's why in general the same stabilizers that you can add to diesel can work fine with biodiesel.

The oxidation of the fatty acid methyl esters is different, and the current additives have been developed for RMEs. Oxidation will lead to fatty acids, combined with the higher water content of biodiesel will lead to increased corrosion, especially Zinc-based ones.

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Zinc based whats? Stabilizers?

Feel free to ask anything else, but I think that 2 problems in the US exist with biodiesel: lack of mandatory, standarized testing and long term experience with stability of SMEs and following corrosion/lubrication problems, especially with PD engines.

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I agree with you about the first one (lack of mandatory testing - the testing is standardized though), but not the second. SME has been thoroughly studied for over 10 years. There may not be long term studies of SME in PD engines - but operationally SME and RME are so similar that it shouldn't have any bearing.

VW AG is looking into "sunfuel", which makes use of all organic waste (say the whole plant instead of the vegetable oil only) and to synthesize diesel from it. The advantage is like for synthetic motor oil, predictable stability and behavior. But that will take time.

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Yes, they're looking into gasification of biomass followed by Fischer Tropsch synthesis. The biggest problem is that it's a rather expensive process.

Audi5000TDI said:

For whatever reason, I'm sure it's valid, Bosch doesn't just make this stuff up or pull a number out of their ass for what blends of Rapeseed Methyl Esther or Soy Methyl Esther is acceptable in Bosch Injection equipment.

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You're being naive if you think that Bosch, or any company, requires thorough testing before making such statements or warranty proclamations. In general, companies look for any excuse they can come up with to deny a warranty. Biodiesel just presents them with a nice opportunity to do so.

I'm certain wear tests and corrosion test have been performed and the results logged and analyzed before release to the public.

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Such tests have been done by independent researchers on all manner of fuel systems for over 10 years. My issue with Bosch is that they are making claims that contradict the results of those tests (some of which were done on Bosch fuel injection systems), and basic science. To me, that clearly indicates that they aren't making their warranty refusal claim based on the science, but rather are making the warranty refusal claim because they'll take any opportunity they can find to deny warranty service, and are trying to fudge the science to back up that decision.

NHMike, how can you possibly make such statement and override Boschs fuel recomendations for a blend of up to B5 in the USA?

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Because I'm quite aware of the 10+ years of studies that contradict the claims Bosch makes to try to deny their B5 stance.

Put your money where your mouth is.

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I do - I've been burning B100 in both of our cars for nearly 4 years. Not a single problem.

Here is what happens when you run B20, through heat cycles as observed in a TDI where the fuel is heated and goes back into your fuel tank. Pages 5 and 6 describe the problems with B20 and cyclical drive and shut off, drive and shut off. This is summarized test results by Bosch and based on Soy Based Methyl Esther fuel.

http://www.arb.ca.gov/fuels/diesel/092904biodsl_bosch.pdf

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What you keep ignoring is that Bosch intentionally did their testing with poor quality biodiesel. Look at slide 3 - they focus on the problems bad quality biodiesel can cause (free glycerin, residual alkali, oxidized fuel, etc.). Sure, we know that bad quality biodiesel can cause problems, just as bad quality diesel can. The problem is that Bosch tris to claim that those problems they saw with bad quality bio are indicative of biodiesel use in general, which completely contradicts all of the studies done by independent research groups for 10+ years.

Could someone with Euro ETKA please get the part numbers that differ between a RME MkV Golf PD100 in Germany and a non-RME MkV Golf PD100 (again, in Germany)?

Is there a way to search ETKA for "different parts between x model and y model"?

Alternately, if they're using different engine codes, what are those engine codes?