B5 Biodiesel - 2013 Volkswagen Passat TDI Long-Term Road Test

2013 Volkswagen Passat TDI Long-Term Road Test

2013 Volkswagen Passat TDI: B5 Biodiesel

May 2, 2014

2013 Volkswagen Passat TDI

I'm sitting in my brother-in-law's San Jose, CA living room looking for any excuse to bail. After five hours of extended family time, I need a break. So I ask if there's a gas station around that sells diesel. Yesterday I had driven our long-term 2013 Volkswagen Passat TDI up to his house from Los Angeles and we were making the return run later today.

"There's one about a mile away", he says. "But we should fill it with biodiesel."

"From where?" I shoot back.

"There's a pump for the stuff over by the freeway at a Chevron station," he says.

"I'm intrigued. Let's go," I say. "But before we do, let's check the VW's owner's manual."

And there it clearly states, "Diesel fuel with concentrations of methyl ester biodiesel higher than 5% (B5), such as B11, B20, or B100, are strictly prohibited."

Hmm. We drive over hoping the pump is dispensing B5, but it isn't. It's selling B20 along with a second pump for E85. Although the sign says it's compatible with "any diesel vehicle" I pass.

Turns out the Propel (propelfuels.com) branded pump is one of seven located in California's Bay Area, including three in San Jose.

Back home I read up on the subject. It's very unlikely one tank of B20 would have harmed our Passat TDI. However, constant use may ultimately contaminate the engine oil which would lead to engine wear and eventual failure. I'm still intrigued, however. We're going to test our Passat TDI on B5 and see what it does to our MPG.

2013 Volkswagen Passat TDI

2013 Volkswagen Passat TDI

Scott Oldham, Editor in Chief @ 18,710 miles


  • And here I always thought that you could run a diesel on used cooking oil with no ill effects. I believe you guys ran an extended biodiesel test on your 2011 Jetta TDI, using at least B20, and possibly higher concentrations, with no damage to the engine noted. Isn't that the same engine as in the Passat?

  • hybris hybris Posts:

    Very miss leading on the biodiesel claim especial since so few people actually bother to read the owners manual.

  • actualsize actualsize Posts:

    "No ill effects" isn't quite true. It will run, and run well, but there can be long-term ill effects IF the vehicle isn't set up for it. Chief among them is bio's purported ability to wash the cylinder surface and get past the crankcase, thereby contaminating the oil. Special oil formulations and/or shorter oil change intervals can counteract this. It's not insurmountable. In fact our new Ram 1500 Ecodiesel CAN run on B20 per the owner's manual with no warranty implications, but Volkswagen will only go as far as B5, which is but one example of how the signage on the Propel B20 pump is absolutely misleading.

  • actualsize actualsize Posts:

    But I have a plan...

  • kirkhilles_ kirkhilles_ Posts:

    Yeah, I'm VERY surprised at that sign. I foresee a class action lawsuit when drivers fill up using that every tank and eventually run into engine problems.

  • What was the price of the bio vs. the regular diesel per gallon?

  • 12vdiesel 12vdiesel Posts:

    Every VW that I have worked on that ran biodiesel has developed a fuel injection pump leak. Is destroys the seals. I wouldn't run it in a VW diesel at all.

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