Winter Rx for Biodiesel

1984 Mercedes 300D in snow - diesel in winter
1984 Mercedes 300D in the winter snow. photo © Adrian Gable

Diesel engines are kind of finicky. Truth be told, they like it hot, really hot. In fact, diesels rely on heat (along with substantial compression) to fire the very fuel that they burn. There is no spark plug to ignite the fuel—the presence of plenty of heat coaxes the fuel to burst into a fury of power that shoves the piston down.

Sound like the start of a captivating novel? No, sorry to disappoint, it's just pure physics in action.

So maybe you can see why winter weather is so difficult for diesels. . . cold fuel in a cold engine makes for a mighty cranky vehicle, and biodiesel in winter just adds to the angst. Read on for the low-down on keeping the fuel flowing and your engine roaring.

Keeping the Fuel Flowing

The aforementioned problems seem daunting, but fortunately, lots of solutions exist. The easiest answer is to create your own winterized biodiesel by mixing it with winterized petro-diesel. If you're buying B10 or B20 from a retail pump though, the winterization is probably already done.


Anti-gel additives chemically alter the fuel to inhibit the formation of wax crystals, but they're not all created equal. Most of those available are designed for petro-diesel, yet they don't do much for biodiesel. However, through diligent research and development, several companies have created formulas that will do the trick on biodiesel.

Biofuel Systems Limited has a product called Wintron XC30 that they claim will lower the pour point (a pour point depressant) on 100 percent biodiesel and all blends.

Power Service Products Arctic Express Biodiesel Antigel is effective on biodiesel blends up to B20.

Among Lubrizol's list of environmentally compatible fluids is 7671A, another pour point depressant that is effective on methyl esters, the chemically correct name for biodiesel.

Though we don't have personal experience with any of these specific products, we have used Power Service's Diesel Fuel Supplement and Cetane Boost with reasonable success. After many years of experimentation, we have found that using a 20 percent mix of our own homemade biodiesel blended with winterized petro-diesel and the appropriate amount of anti-gel additive has kept us puttering through the long, cold winter—gelling problems virtually eliminated.

Heating the Fuel

If you live where severe winter weather is common, you may want to investigate the possibility of using an electric fuel heater.

There are heated fuel filters available that can run off your vehicle battery or be plugged into household current. There are also heating pads and heating probes that can be applied to the fuel tank, again running off the vehicle's 12-volt battery or household current.

An additional way to heat the fuel is with an engine coolant heater that can warm the fuel by circulating hot engine coolant around the fuel filter. Of course, this is a bit of a chicken and egg thing: While this will keep the fuel warm while the engine is hot and running, it won't help get it started in the first place.

Keep the Whole Engine Warm and Toasty

If your vehicle has an electric block heater (a heating element that is installed in the engine block and immersed in the coolant), it can be a major help.

These heaters warm the entire engine to ease starting. They operate on household current, and on bitterly cold days, consider plugging it in for several hours or overnight if you need it first thing in the morning. For such a simple concept, block heaters are an amazingly effective way to keep the entire engine warm for easier starting.

Be sure to check page two of this article for our Quick Fixes

Quick Fixes

If you suspect the fuel has gelled, but is not solid in the fuel lines, try these quick fixes to get back on the road again:

  • Use a hair dryer on high. Blow hot air over the pump and fuel lines for 5 to 10 minutes to liquefy the fuel. If the fuel is just slightly gelled, but not solid, this will get things running again. Another possibility is to pour several pan-fuls of hot water over the fuel filter, pump and injector lines (remember to keep it away from the alternator though).
  • Cycle the glow plugs. Yes, switch the ignition on and wait for the glow plug light to go out and repeat two or three times before starting the engine. That can help get extra needed heat into the combustion chamber to get the engine started.
  • Top off your tank. If the fuel has gelled and you suspect there is too high a percentage of biodiesel in the tank, top your tank with winterized petro-diesel fuel plus a good dose of anti-gel additive to prevent it from gelling again.

For general diesel cold weather issues, be sure to check out these three things to be aware of.

mla apa chicago
Your Citation
Gable, Christine & Scott. "Winter Rx for Biodiesel." ThoughtCo, Feb. 4, 2017, Gable, Christine & Scott. (2017, February 4). Winter Rx for Biodiesel. Retrieved from Gable, Christine & Scott. "Winter Rx for Biodiesel." ThoughtCo. (accessed December 17, 2017).