Biodiesel Warranty Issues: What You and Your Dealer Should Know Before Your Car Breaks

Biodiesel Warranty

The Northwest Biofuels Association has produced a joint letter about biodiesel warranty protocol intended to set the record straight for auto dealers (and everyone else that’s confused about the issue).

Recently, I wrote about how biodiesel’s new ASTM standards could go a long way in improving warranty coverage for biodiesel use in your new car. NW Biofuel’s letter goes into a little more detail, and gives you a reference you can give to your dealership or keep in the glove box. Here’s what you should know:

  • Whether or not a biodiesel blend is “recommended” by your automaker is separate from the question of whether the use of biodiesel affects engine warranty coverage. Make sure you know exactly what your automaker specifies.
  • Because vehicle warranties only cover parts and workmanship, fuel is not covered under any vehicle warranty.
  • Conversely, if consumers that use biodiesel have an engine failure unrelated to the use of biodiesel and the cause is found to be faulty parts or workmanship, then the failure would be covered by the warranty.
  • If a customer brings in a vehicle that has used biodiesel and the customer is told that the warranty is voided solely because the customer is using biodiesel, this violates the Magnuson-Moss Warranty Act.
  • A vehicle’s warranty cannot be voided solely due to the use of biodiesel.

The letter also gives dealerships testing protocol to follow in the event that off-spec biodiesel could have caused a problem.

Engine manufacturers explain that fuel is a not a warranty issue. Still, they typically define what fuel the engine was designed for and recommend which fuel to use. As biodiesel has gained in popularity, Original Equipment Manufacturers (OEMs) have been testing their diesel equipment with different blends of biodiesel. OEMs have agreed that a blend of 5% biodiesel and 95% petroleum diesel (B5) is approved as a recommended fuel, provided that the biodiesel fully adheres to the quality standards specified by the American Society of Testing and Materials (ASTM) D 6751. Note that all biodiesel sold in the Portland area has been rigorously tested to assure that it meets ASTM standards.

The letter was a written in close collaboration with Oregon auto dealers and Oregonian biodiesel distributors, and is intended for national adaptation and distribution.

Read the letter and learn more about biodiesel on the NW Biofuels Association Website and other materials on Gas 2.0 (be sure to stop by our Biodiesel Guide).

More Posts on Biodiesel and Warranty Issues:

Photo Credit: Northwest Biofuels Association Website



In a past life, Clayton was a professional blogger and editor of Gas 2.0, Important Media’s blog covering the future of sustainable transportation. He was also the Managing Editor for GO Media, the predecessor to Important Media.