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I pulled up to a Murphy gas station with a diesel pump. ON the pump it had a disclaimer that said the fuel contained Biodiesel and that I should consult my engine manufacturer before using, etc. The price was .10 cents cheaper than the diesel at race trac down the road, but I didn't bother filling her up at the murphy station without asking you guys here.

I looked all over the pump for a sticker that would say how much biodiesel was blended, but there was none. I did see a dump truck fill up there a little while later, so people are using it. Given that this car has so many miles, and its 10 years old, I didn't want to risk it.

My only understanding of biodiesel is that it requires multiple filters, but that's only if you are using 100% biodiesel. I don't know if you need to adjust anything else, etc., so please enlighten me!

Is blended biodiesel (whatever the concentration) safe for this car?

2004 VW Passat 2.0 TDI with nearly 200k miles.
 

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Biodiesel is 100% fine in a 2005. VW calls for a limit of B5 but they always said that even though B100 ran fine. The issue is that on a car with 200k miles, it probably has some buildup and more than B20 for a while will clean it out. This crud is caught by the fuel filter, requiring more frequent changes. B100 is when you have to start to think about a fuel pre-filter until it's cleaned out.

Only possible issue is if your oil starts to rise = biodiesel doesn't evap as fast and is accumulating in the crankcase.
 

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Thanks for the info! Glad to know it's ok. The fuel filter is going to be changed at the next oil change.

What do you mean by "oil starts to rise"? You mean the oil pressure?
 

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No oil level. diesel normally leaks past cylinders into crankcase. Bio doesn't evaporate as fast so it can sometimes accumulate and contaminate the oil over 10,000 mile normal oil change interval. Depends on how tight the engine is, duty cycles, bio %.
 

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Here in Minnesota all diesel is blended with up to 20% (it varies, no precise amount). There is a place that sells B99 and my son has filled his '06 Jetta there many times with no ill effects.
 

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If the pump doesnt specify how much Bio is in the fuel, I would assume there is no more than 10%. Due to the current EPA ULSD mandates, and all the emissions systems required on new manufactured vehicles whatever is at the pump should be safe for new vehicles. As for any vehicle 06 and older, it will run perfectly fine.
 

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In Ohio Murphys has 5 to 20 percent Bio Diesel blended into Regular Diesel Fuel and I imagine it is close to 10 percent because the higher levels would make them less money but who knows politics in farm states may want more Bio Diesel put in.
 

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Well I have used their fuel in 82,95,06,09,13 VW Diesels and they all did fine and used diesel in 85 Ford Escort Mazda Diesel.So I don't think you will have any problem. But I change the fuel filter every December or January before the Winter Season.
 

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Chitty, I was not aware that biodiesel could make oil in a car without newer exhaust systems. My impression was that bio made oil during regens, when it just takes more fuel to get the temps,needed to oxidize the soot in the DPF.

MnTom, the reason why your son can fuel his pumpe duse 06 Jetta with bio is that it does not have a modern exhaust to cause above probs. I run it in my 06. But not my 14 Passat yet. I'll likely run b20 once I put some more miles on it and have a good,solid baseline for petrodiesel.

Bio is a good solvent, it will free up gunk in the file system as others have said. Buy extra filters and don't go on a big road trip when switching. Also biodiesel eats rubber hoses,and seals, so a,flourocarbon like viton is a good,replacement hose.

I run thousands of gallons a year on my farm. I had to replace the entir field system on my combine, and pull the tank and have it coated. I drain the tank for the winter and run so,me petrodiesel through it so that it sits in the system rather than the super hydrophilic biodiesel. Hope this helps. The pump you are referencing prolly has low amounts, like an ethanol additive. Usually 5-10%, maybe 15 once in a while. I would consider that a superior fuel to straight ULSD, because of increased lubricity.

Cheers-
 

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It does, just not as much as the new DPF equipped engines that use post injection combustion. There's always some fuel and soot leaking past the piston rings and getting into the oil but it's not enough (or shouldn't be) to cause noticeable accumulation in a non-DPF car. It still contaminates the oil just like regular diesel will.

The solution is a separate high pressure fuel injector downstream of the cylinders but that didn't work very well in the 1996 Passat (albeit with old tech) and it costs more money so it's off the table for now.
 
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