Awake at the Wheel

Biodiesel innovation is occurring at blinding speed. The latest: Prince Charles has developed an insulating artificial turf, suitable for garage wallpapering, that will keep his B100 powered Range Rover and Jaguar above the dreaded Cold Filter Plug Point. Many of you northern climate types may be familiar with the plug-in engine block heater. That is history. The Moore’s Law of biodiesel cold flow properties has been defined, and it is astroturf.

Ok. In layman’s terms, what happens to high blend biodiesel at cold temperatures? B100 soy biodiesel begins causing problems at 30 degrees, +/- 5. At this temp biodiesel begins to form crystals in the tank. These crystals are too large to fit through the fuel filter. Eventually, they will clog the filter and stop the flow of fuel to the engine. The temperature at which this happens is called the Cold Filter Plug Point (or CFPP). When asking your biodiesel supplier about cold weather performance, ask for the CFPP test results. CFPP is a more appropriate metric than Cloud Point (CP) when considering biodiesel cold flow performance, because it is the true operating limit.  If you operate in temps below the advertised CFPP, you should consider a lower biodiesel blend level.

Do B100 additives help? Our research has shown that cold weather additives don’t have any affect on biodiesel above B60. Why? The additive is working on the diesel portion of the blend, but not the biodiesel. The most effective current additives remain petroleum based- petrodiesel (aka D2) or kerosene (aka D1). The chemists promise new and improved non-petro additives soon.

What to do if your vehicle stops? Warm it up. And don’t excessively crank the engine.

The National Biodiesel Board randomly tested biodiesel for quality this fall. The results were discouraging (.pdf). So remember these keys for winter biodiesel driving:
All biodiesel is not created equal. Buy from a reputable retailer or supplier.
Plan ahead! Blend with D1 or D2 as temps are forecasted to drop below 40.
If buying pre-blended fuel, ask your supplier about the blend stock, winter additives and CFPP rating.
Demand ASTM certified B100.