How Biodiesel Affects Diesel Cars

• Posted on Autos.com Editor
• in Car Buying
• on October 7, 2013

Drivers of diesel cars who are thinking about using biodiesel instead of conventional diesel often wonder of the effect it would have on their car’s engine. There has been suspicion and uncertainty of using biodiesel in cars running petroleum based diesel for a long time. Auto manufacturers often caution against using biodiesel, warning that use of any blend higher than B5 (5% biodiesel, 95% regular diesel) will cause gaskets to fail and lines to be clogged, possibly voiding out any remaining car warranty. While some might sound ominous, much of it is not as serious as it sounds, and in most cases is inaccurate.

What Is Biodiesel?

Biodiesel is diesel fuel manufactured from renewable resources like soybeans, canola or used cooking oil. It contains no petroleum, unlike conventional diesel sold at fuel stations. The list below are some things to expect when switching over from conventional diesel to biodiesel.

• Cleans Engine – Biodiesel is a solvent (as is diesel, however more so) and when used in a diesel engine initially, can “clean out” an engine of deposits. Using biodiesel will not dissolve plastic parts or gaskets in a diesel engine. What it can do is dissolve deposits that have built up in the system, dislodging them and sending them through the lines.
• Fuel Filter Change– The fuel filter may need to be changed sooner than expected, due to the possibility of cleansing action of biodiesel as stated above. This will only happen when switching over to biodiesel initially. You can expect normal maintenance of the fuel filter from then on.
• Better MPG– Drivers using biodiesel have reported better MPG compared to standard petrol based diesel. Because biodiesel can clean an engine of deposits, it can increase the efficiency of the engine, supporting the benefits of biodiesel fuel efficiency.