New To Bio-Diesel? Here’s What You Need To Know To Keep Your Used Semi Running Smoothly In Cold Weather

Are you about to become the owner/operator of a used semi truck that will frequently travel through cold climates? Do you want to boost the truck's fuel efficiency with the use of bio-diesel, but don't know much about it because you've always filled up with petro-fuel alone? If so, the following information is for you.

Bio-Diesel Gels Faster Than Petro-Diesel

Just as petro-diesel has bits of paraffin that solidify in cold temperatures, bio-diesel has bits of glycerin that do the same. The main difference is the temperatures at which the gelling occurs. 

While it can occur faster under rare conditions, untreated, standard #2 petro-diesel will usually be safe from gelling until temperatures drop to between -18 and 20 degrees Fahrenheit. Most untreated bio-diesel, on the other hand, will begin to gel up at just 33 degrees Fahrenheit. 

When Blending For Cold Weather, Keep Your Bio-Fuel Under 5 Percent

Studies show that the lower the percentage of bio-fuel in your fuel tanks, the less your fuel's overall cold-flow (lowest operable temperature) will be affected. If you're worried about fuel-gelling, stick with a B2 or B5 blend. B2 blends are composed of 2 percent bio-diesel and 98 percent petro-diesel, while B5 blends are 5 percent bio-diesel and 95 percent petro-diesel. 

If You Must Use B20, Take Extra Precautions

After a 5 percent mix, the next standard bio-diesel mix is 20 percent bio-diesel to 80 percent petro-diesel. At this point, there's enough bio-fuel in your tanks to seriously increase the risk of gelling. While a truck running B20 or higher will get great fuel mileage, it will also freeze up on the side of the road unless the driver takes some added measures.

Cold-Weather Additives. Cold weather additives work to break up and dissolve the solidifying molecules that result in fuel-gelling. However, since the molecular makeup of petro-diesel and bio-diesel are quite different, standard cold weather additives don't work very well for trucks running bio-diesel.

If you're running a blend of petro-diesel and bio-diesel, you'll still need petro-diesel cold weather additives in cold climates, but you'll also need to dump some additives specifically formulated to lower the gel-point temperature of bio-diesel fuel into your tanks.

Winterized Bio-Diesel. Another way to lower the cold-flow of your fuel is to buy a winterized bio-fuel blend. It's available in all the same blend quantities as regular bio-fuel, but it goes through an added process.

The fuel is heated up and then cooled to temperatures just below its freezing point. As the fuel is cooled, the fats in it sink to the bottom of the mixture. The liquid fuel is then separated from the solids, and the solids are discarded. The resulting, low cold-flow fuel can then be mixed with petro-diesel, providing you with cold-tolerant mixes of B20 or higher.

Filter Heaters. For the coldest of climates, fuel filter heaters provide optimal protection against bio-diesel gelling. These silicone pads wrap around your semi truck's fuel filter and are held in place with adhesive strips. Once the pad is in place, all you need to do is connect the wire to your already on-board battery, and you'll have a constant flow of heat delivered right to your filter canister. When temperatures rise, you simply disconnect the wire from your battery; you can leave the pad right in place for the next time you need it.

If you're buying a used semi truck and you plan to use bio-diesel fuel to power it, you've got to understand the differences between petro-fuel and bio-fuel as they relate to cold climates. Bio-diesel can make your truck run cleaner and more efficiently, but when temperatures drop, you'll need to buy winterized bio-fuel, stick to a low mix rate of bio-diesel, and/or protect your fuel from gelling with a fuel filter heater.

Now that you're armed with this information, you're ready to get your used semi truck from a dealer like