[michelle123]

Hi,
I’ve been driving an 85 Mercedes Wagon on B99 (from a pump—it’s made locally) for the past four years. I like the car a lot but at this point would like something newer. I’m interested in buying a 2011 VW Jetta Sportwagen so I went to the dealer yesterday to drive one. I loved it and want to buy it! But, when I mentioned biodiesel I was told that I would need a new metal fuel tank that costs around $800. I cannot find any info about this online. Has anyone ever heard of this? I know in older models fuel lines, gaskets, etc sometimes needed to be replaced . . .but not a fuel tank. What do you think? Or are there any other modifications that I need to make? The salesman I talked to seemed to know a lot about this type of stuff—he’s been driving VW’s and Mercedes for years and uses both biodiesel and diesel. I’ll ask the dealership for more info but thought you all might have some answers.
I have also read online that VW only allows B5 and that if you use higher blends it voids the warranty. I forgot to ask and the salesman did not mention this. Is this true? If so, can I run B99 and then just empty the tank and refuel with diesel before I take it in to be serviced? Obviously, the 3 yr warranty sounds great and I don’t want to ruin it.
Thanks for any advice you can offer!
Michelle

 

[chittychittybangbang]

If the saleman could point you towards references saying that the fuel tank needs replacement that would be helpful. The fuel tank is plastic and I can see no reason why it would need replacement at all.

VW has never allowed more than B5. In the past, good biodiesel could run fine with no ill effects. The engines should still run fine but the issue now is that the post combustion injection of fuel dilutes the engine oil to the point past tolerable limits and the diesel particulate filter could possibly not work as well due to the properties of biodiesel. See this FAQ article for more on it: http://www.myturbodiesel.com/1000q/DPF-Adblue-FAQ-VW-Audi.htm

Also see the sportwagen buying guide for some other general tips: http://www.myturbodiesel.com/1000q/a6/2011-VW-sportwagen-TDI-buying-guide.htm
welcometomyturbodies

 

[michelle123]

thanks!

Hi-Thank you so much for your help . . . I really appreciated your prompt reply! Your advice--and the links to the articles--have been very helpful. After receiving your note I read more about these issues online and definitely understand your points. I don't want to mess up a lovely new car!
Thanks again,
Michelle

 

[tanderegg]

Is the fuel oil used in home furnaces an equivalent to what is being sold at the pump? Will it run the tdi in an emergency situation? I know that off highway diesel used for construction equipment has a dye in it but I think its the same type of diesel autos use.

 

[Keithuk]

Heating oil is generally paraffin (kerosine) based which will run in a diesel, you can add it as a winter fuel to reduce freezing as well but obviously the tax is less. In the UK Construction equipment or anything that doesn't normally drive on the road is called red diesel because of its red dye, again they is much less if any tax on that but its the same a road diesel.

 

[Aseras]

The problems isnt the tank or even the fuel itself. the engine will happily run on almost any fuel oil you can put into it. The real issue is the emissions crap and the computer. The newest VW's all have a DPF which will plug up very fast on more than b5, or any "off road" non ultra low sulfur fuel. It will run fine though, just at the cost of ruining your dpf which is very expensive. There's a huge interest in europe to do dpf deletes and run SVO or UMO and have the computer reprogrammed to delete the dpf codes and programming. There's substantial horsepower and mileage gains as well when the dpf restriction is gone. However, "tampering" with emissions crap is illegal in the US. If you buy one new it'll be pretty hard to deny who did it. Buying used gets you plausible deniability.

 

[Audi5000TDI]

Hi,
.
I have also read online that VW only allows B5 and that if you use higher blends it voids the warranty. I forgot to ask and the salesman did not mention this. Is this true? If so, can I run B99 and then just empty the tank and refuel with diesel before I take it in to be serviced? Obviously, the 3 yr warranty sounds great and I don’t want to ruin it.
Thanks for any advice you can offer!
Michelle

The answers are

Yes, VW only allows up to B5
.
No, you can't go empty the fuel tank of biodiesel and then fill it up with diesel before being serviced. You are voiding your warranty by doing so.

Please don't go buy a TDI that is newer than a 2003 to run on biodiesel blends higher than B5. You need a 2003 or earlier model. The later models need much higher quality fuel that does not clog the fine mesh intake vents on the PD injectors, nor causes corrosion, something only D2 is sufficiently clean and has higher quality control standards.

 

[Cstdi]

heed the advice on the DPF here. No more than B5. Just to give you an example, running B20 for several months with a DPF on my 06V10TDI resulted in DPF backpressure issues and performance issues (the DPF system can not handle it). No issues dropping down to B5. In terms of running LSD, if you can still find it, according to my 06 manual (at the time of the manual printing, the US was late in switching the pumps over to ULSD and the Motherland knew it) the VW advice was that the DPF requires ULSD but can run on LSD if necessary. However, it also said that use of LSD will result in the premature expiration (I think that was the word they used) of the DPF