Corrosive: the downside to using Biodiesel

Posted By on June 7, 2006

Biodiesel Samples B100/B20
I’ve been using biodiesel for about 4 years in two of our Volkswagen TDIs, a John Deere and even in a Bobcat skidloader. Saturday I had my first fuel line casualty using B100 (or B99 recently) in my 1980s John Deere diesel while mowing. Yes I knew the fuel lines were not of a material that could withstand the corrosive effects of methanol used in the production of biodiesel but continued to use it nevertheless. Now what?

Viton hoses are the fuel line of choice but shockingly are very expensive if you need more than a foot or so of 5/16″ inside diameter hose. After looking at a few local speed shop options I decide to purchase some from McMaster-Carr and plumb it with some 5/16″ copper water line. (I know … copper isn’t the preferred material for biodiesel either) Put things together tonight and everything seems fine.

Blue Fuel LinesAfter I placed my order, a friend at the TDIClub posted a photo of his new ‘biodiesel resistant’ Polyurethane blue colored hose at Procycle. It is reasonably priced and looks like a good choice if using more than a few feet of fuel line. Perhaps the next time I need to replumb I’ll opt for this? Thanks for the advice and the photo Fortuna Wolf.

EDIT 6/10/2006: A couple of comments in regard the the polyurethane hose by a few valued TDI contacts have pointed out that even though polyurethane is more resistant to biodiesel than many polymers, it still may not be the best choice where one has high percentage biodiesel, ethanol or methanol alcohol use. In a follow up message from Fortuna Wolf at the TDIClub, he stated that “I had an order from McMaster and bought a foot of their blue polyurethane hose to see it. It is NOT the same as the procycle fuel lines. Its a much softer and lower temperature plastic.”

Also thanks Mike for your regular comments to my posts … your insight and knowledge is appreciated. Thanks for the backup links when commenting; they are most valuable.


  • mike

    This is the thread it came from.. but I noticed item 55 discourages use of these hoses

    Almost nothing in the tdi world is straight-forward, simple, and agreed upon…ugh

  • Thanks Mike … included an edit based on some messages from Fortuna Wolf and your great comment. Thanks.

  • How much to really get into Biodiesel, using McDonalds and all?

  • As a realistic ‘alternative fuel’ or ‘additive’ to impact the petroleum use we’ll need to look at a better feedstock source. See link:
    On the other hand, there isn’t anything wrong with recycling used cooking oil for a biodiesel fuel additive … and we create a lot of waste oil everyday.

Desultory - des-uhl-tawr-ee, -tohr-ee

  1. lacking in consistency, constancy, or visible order, disconnected; fitful: desultory conversation.
  2. digressing from or unconnected with the main subject; random: a desultory remark.