Cold weather diesel information

Posted on January 9th, 2009 by admin0 under News.

How is your diesel/bio-diesel running this winter?

            Be mindful of these three issues on your diesel before cold weather strikes and you’ll eliminate common diesel cold weather starting problems and at the same time help your diesel provide you with safe, reliable travels throughout the most challenging season of the year.

The Fuel Itself

            Cold weather starting problems, sluggish diesel fuel, the necessity to use anti-gel additives . . . You’ve probably heard that the biggest problem with running diesels in cold weather is the tendency of the fuel to gel. No. 2 diesel (the grade recommended for most passenger vehicles) contains some naturally occurring paraffin (wax) and as the temperature drops, this paraffin crystallizes and affects the fluidity of the fuel and may cause hard starting and eventually lead to filter plugging. Unfortunately, this problem is exacerbated when biodiesel enters the equation—biodiesel tends to gel at a slightly higher temperature than diesel.

            Luckily these problems are fairly easily solved. Regular diesel fuel is “winterized” or seasonally adjusted at the distributor before it’s delivered to the pumps. Winterizing is done by mixing pump No. 2 diesel with No. 1 diesel, its more refined cousin. Winterizing diesel fuel is done to maintain the cold weather flow characteristics, and the ratios vary depending upon regional distribution. To effectively use biodiesel in cold climates, it must be mixed with winterized diesel in varying percentages, which, once again, are regionally dependent.

Tip: It’s a good idea to add diesel fuel cold-weather treatment or an anti-gel additive to ensure that you maintain the low temperature flow characteristics of the fuel. Available at auto parts stores and department stores, anti-gel treatment may be conveniently kept in your trunk and poured directly into your diesel’s fuel tank before filling up.

            There is ongoing experimentation and research on the cold-weather treatments for biodiesel blends higher than B20. ( Have you pulled up to a fuel station and noticed B5 or B20 on the pump? Yep, that’s biodiesel, an alternative fuel made from vegetable oil or animal fats. That number following the “B” says that it’s blended with petroleum: B5 is 5 percent biodiesel and B20 is 20 percent. B100 is 100 percent biodiesel, no petroleum–also known as neat biodiesel.)

Are Your Glow Plugs Happy?

            If your vehicle is equipped with glow plugs, they need to be in good working condition, along with the glow plug relay. Glow plugs are small electric heating elements (they look like mini spark plugs that are installed in each cylinder.) They are on a timed circuit and activate for a few seconds just before the engine is started. The colder it gets, the longer those glow plugs need to stay on to pre-heat the combustion chamber for a smooth start.

Tip: If your glow plug light on the dashboard doesn’t light when the ignition is switched on, that’s an indication that you may have a glow plug out—and a noticeable engine stumble will be another big indicator. Even one glow plug out may prevent the vehicle from starting


Check that Battery

            When it’s cold outside, everything is a little more sluggish—the fuel is cold, the engine oil is thick and even your car’s cranky. Will she start? Make sure the battery is in good condition. It needs to hold a good charge to provide adequate cranking amps—a diesel requires upwards of 1,000 cold cranking amps to get that engine running. A stout battery provides the sustained cranking power and duration needed to get the engine running in cold weather.

Tip: Check the label on the battery to see how old it is. Those pop-out dots should indicate the month and year it was installed. The label should indicate the life expectancy; they usually range from 48-72 months. If you suspect your battery is getting near the end of its life cycle, it may be a good idea to replace it before cold weather strikes.

            Algae growth in the fuel tank and lines is a potential problem. Indeed, it may seem odd at first—how can anything grow and live in diesel fuel—but it is true, especially in warm and humid climates. And algae can live in petro diesel as well as biodiesel.

            Algae, which looks like a dark green to black slime, may grow and thrive in the fuel tank and lines. It can be swept along with the fuel as it travels through the system, eventually getting trapped by the filter. As it grows and accumulates over the long haul, the algae can clog the fuel filter and prevent fuel flow.

            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.


Article provided by Christine & Scott Gable,



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