Volkswagen Jetta TDI warranty is voided by biodiesel.

[NNadir]

I asked Volkswagen if fueling a Jetta with biodiesel would void the warranty. Their response:

"Thank you for visiting the Volkswagen Web site. We appreciate your inquiry on Volkswagen's position on using biodiesel fuel.

B100 stands for 100% biodiesel. It is a diesel fuel derived from biomass feedstock such as soybeans. It can be blended with regular diesel fuel (B20 = 20% biodiesel/80% regular diesel, for example). In Europe our diesel engines are certified to operate any blend of the biodiesel that is available in Europe. European biodiesel is different than biodiesel in the U.S. since it is produced from different feedstock (the rapeseed plant versus the soy plant).

Our parent company does not agree with the specifications for biodiesel in the U.S. and does not recommend its use in any percentage. Using biodiesel will invalidate our warranty.

If you have any further questions or concerns, please contact Volkswagen
Customer Care at 800-822-8987.

Thank you for your submission."

A dubious policy at best. That reduces the the environmental advantage of buying a Volkswagen.

Does anyone know of the rulings of other companies on this matter?

[BlueEyedSon]

1. Ok, I'm out (on VW cars).... are ANY US market cars certified for B100???

TIA.

[One_Life_To_Give]

2. Poor Lubricant maybe?

Curious that European Biodiesel is OK, but the US standards for biodiesel may not be OK. Would need to see more details on the specifications for each. But since diesel fuel is also a lubricant for the fuel delivery system it could be that it's lubricating properties or particulates in the suspension cause concern for the engineers.

Without more information can't tell if this is VW or API who should be faulted for this.

[htuttle]

3. Does it have to do with the Sodium hydroxide (lye) content?

That's the only thing I can think of in biodiesel that might be harmful to a car. If you make biodiesel (in your garage) using lye, and don't wash the lye out appropriately, traces will remain in the fuel and degrade rubber fuel lines.

But I didn't even know that the US HAD biodiesel specifications....

:shrug:

[cprise]

4. This was a big issue 2 years ago

Few people pay attention to it now. The following is how I understand it:

VW has cited "differences" between rapeseed and soy biodiesel, but has not explained what that means nor shown any functional difference. Through all this, none of their statements about biodiesel has mentioned the U.S ASTM D6751 spec for the fuel -- not even once.

All biodiesel sold commercially in the U.S. must meet the above spec. And according to the National Biodiesel Board, "The use of biodiesel in existing diesel engines does not void the parts or materials workmanship warranties of any major US engine manufacturer." So that leaves European mfgs in question (VW and Mercedes) both of whom have recently decided to patent a biodiesel competitor called SunFuel. In fact, these two are now starting to discourage biodiesel in the EU. IMHO when 2006 rolls around, eveneryone and their grandma will want to market diesel cars and it will be these two mfgs against all the others on this subject.

In the real world, I don't think anyone has heard of a biodiesel user being turned down for warranty service by a VW (or any) dealer; not on the VW or biodiesel sites, nor elsewhere. Interestingly VW does not press their position because it probably would be illegal for them to do so, in violation of the Magnuson-Moss Warranty Act. ASTM D6751 describes a fuel intended for general use in diesel engines, so VW would need to prove the spec inadequate, or change the classification of their engines to something other than "diesel" in order to stand behind their statement.

[NNadir]

5. I suspect that VW is being disingenuous but the oil constituents ARE

different.

Rapeseed oil contains about 49% Erucic acid, a monounsaturated C-22 compound which is not found AT ALL in Soybean Oil. On the other hand, soybean oil is 55 percent linoleic acid, a C-18 conjugated diunsaturated compound that makes up only 12% of rapeseed oil. Moreover the gel point differs by a rather large 12C for the methyl ester derived biodiesel. It is -3C for soybean derived fuel and (a much improved) -15C for rapeseed oil.

I very much doubt that these differing parameters have much effect on the compatibility of seals (although it is certainly not impossible) but one can easily imagine that it has a profound effect on the lifetimes of injectors and pumps and possibly other engine parts.

As to whether or not this warranty matter is a "big issue," I suppose this would depend on one's viewpoint and wealth. VW didn't send me the cited email two years ago; I received it yesterday. It is very easy to declare what is an issue when one is speaking of other people's money, just as it is much easier for George Bush to speak easily of the sacrifice of other people's lives in Iraq than his own in Vietnam. Personally I could not afford to challenge VW on the issue. It is easy to imagine that the legal costs of pursuing the matter might exceed the cost of the car which is roughly $20,000. As to what bearing the fact that you or anyone you know have not heard of VW pushing the matter does not mean that the event does not occur. I, for instance, if involved in such a case doubt very much that I would be notifying either you or someone you know. I do know that a manufacturer of a certain widely sold vehicle were systematically voiding warranties on much less valid grounds. If you are an expert in the matter, I would like to test you by asking if you can identify that manufacturer here.

I would suspect that VW's case has much more to do with the nature of the differences in biodiesel production environments in Europe and the United States. In Europe, many countries mandate the use of biodiesel mixes in fuels. (I would applaud similar laws here BTW) This means that the industry is run largely by professionals. Here in the United States, much of the biodiesel is manufactured in back-yard operations. Frankly, as a chemist, I'm somewhat horrified at times when I see the chemical processes used in these operations, and consider the probable lack of validated test equipment to insure product consistency. (I'm even more horrified when I contemplate the potential waste products of some of these processes as point-source pollutants.)

At the very least, as another poster noted here, there may be issues of acidity and basicity that are improperly addressed. These can certainly result in engine corrosion and if I were running VW, I might be concerned.

I am fairly certain that an industrial producer of biodiesel has a much more consistent product than the average American producer. It would certainly be an interesting exercise to analyze samples of biodiesel from differing sources in the US to get an idea of exactly how bad things are in this respect.

Still overall, I have grown considerably in my support for an expanded biodiesel industry both here and abroad, when proper environmental protections and systematized production values are used. I very much doubt that biodiesel represents a macroscopic solution to the greenhouse and energy crises that we face as a species, and I question its long term sustainability, but it certainly is attractive as a bandaid for the time being. I note that the ExternE project indicates that the external cost is considerably lower for biodiesel than it is for petroleum diesel. Moreover in some cases, depending on source, biodiesel can be less polluting in particulates, has no sulfur, and, though it generally is higher in NOx than petroleum, NOx can be fairly easily addressed catalytically.

On economic terms, I think that biodiesel is likely to be uncompetitive without considerable process improvements. It is rather absurd to run a fuel business using batch processes, but I have no doubt that chemists and chemical engineers can manage ultimately a continuous process that will have a smaller environmental and economic impact than the ancient process of saponification/transesterification now employed.

Nevertheless, biodiesel may have a long-term niche in non-transportation uses where No. 2 oils are used, such as in heating applications and certainly in farm based uses.

It may even retain a niche in the transportation sector, if in fact the diesel engine continues to be used by future generations. My favorite wonder fuel, DME, does represent some challenges to engine life owing to its poor lubricity vis a vis its more polluting cousins like biodiesel and petroleum diesel. The incorporation of biodiesel into this fuel, or its use as a pure lubricant is sometimes suggested.

Speaking of DME, Chinese chemists published a wonderful catalytic improvement for the production of DME from syn gas in this month's issue of Energy and Fuels (Energy & Fuels 2004, 18, 234-241). Bless those Chinese. They still respect science in that culture and they're serious about going nuclear. In a few years they will really start to eat our economic shorts so bad that we will quickly find ourselves naked.