How To Keep Diesel From Gelling: What It Is And How To Prevent It In Winter

Table of Contents

1. What Is Diesel Fuel Gelling?
2. Key Cold Weather Diesel Fuel Terms (Cloud Point, CFPP, Pour Point)
3. How Cold Does It Have To Be For Diesel To Gel?
4. Diesel Gelling vs. Fuel Icing (Wax vs. Water Problems)
5. How To Prevent Diesel Fuel Gelling
   1. Add Anti-Gel Diesel Fuel Additives
   2. Use Winterized or Blended Diesel Fuel
   3. Keep The Engine and Fuel System Warm
   4. Proper Fuel Storage and Maintenance (Keep It Dry and Clean)
6. What To Do If Your Diesel Fuel Gels (Emergency Measures)
7. Clean, Prevent, and Rescue

Diesel fuel is the lifeblood of heavy-duty vehicles and equipment, but cold weather can turn this vital fluid into a source of headaches. When temperatures plunge, diesel fuel can “gel”, becoming thick and waxy, which can clog fuel filters and stop engines cold. Unlike gasoline, diesel contains waxy hydrocarbons (paraffin) that solidify in the cold, shutting down trucks, tractors, and generators. If you've ever had a diesel vehicle refuse to start on a frigid morning, chances are the fuel gelled up. Understanding what diesel gelling is, what causes it, and how to prevent it is crucial for anyone who operates diesel equipment.

In this comprehensive guide, we’ll explain diesel gelling in detail, define important cold-weather fuel terms (like cloud point, pour point, and Cold Filter Plugging Point aka CFPP), and outline proven strategies to prevent gelling. We’ll also discuss how specialized winter diesel additives work to keep fuel flowing. By the end, you’ll know how to winterize your diesel fuel effectively, ensuring your diesel engine runs smoothly even in the bitter cold.

What Is Diesel Fuel Gelling?

Diesel fuel gelling refers to the process by which diesel fuel thickens and solidifies in low temperatures due to the formation of wax crystals. Diesel fuel naturally contains dissolved paraffin wax, which is a petroleum-derived wax that improves fuel’s energy content and lubricity. When the weather gets cold enough, this wax comes out of solution and begins to crystallize into solid particles. The fuel will turn from a clear, free-flowing liquid into a cloudy, gel-like substance as more wax solidifies. This solidified wax collects on your fuel filter and in your fuel lines, blocking the flow of fresh fuel and starving your diesel engine leading to shut down or rendering the vehicle useless.

Diesel gelling typically occurs when sitting in the cold for long periods, such as overnight. Once diesel has gelled, you will likely be unable to start your engine. If you are able to start your diesel engine, loss of power and stalling are also common symptoms of gelled fuel.

If you remove a fuel filter and find it choked with an opaque, whitish substance, that’s gelled diesel wax and is a telltale sign that you have a gelling problem. By contrast, normal diesel remains liquid and clear or lightly colored.

Key Cold-Weather Diesel Fuel Terms (Cloud Point, CFPP, Pour Point)

Diesel fuel doesn’t go from perfectly liquid to gelled all at once; it transitions through stages as temperatures drop. There are a few important terms that describe these stages and properties of cold diesel fuel:

• Cloud Point (CP): The cloud point is the temperature at which wax crystals first become visible in diesel fuel, giving it a cloudy or hazy appearance. At the cloud point, wax has begun to crystallize, but the fuel may still flow (albeit with reduced efficiency). For typical #2 diesel fuel, the cloud point is often in the range of about 15 °F to 20 °F (−9 °C to −7 °C), though it can vary widely. Some untreated diesel fuels might even start clouding around 32 °F (0 °C) if they have high wax content or are a “summer” blend. In general, once fuel hits its cloud point, it’s a warning that wax formation has started. The fuel will look milky or cloudy in a clear container.
• Cold Filter Plugging Point (CFPP): As wax crystals continue to form and grow in size, they reach a point where they begin to clog fuel filters. The Cold Filter Plugging Point is the lowest temperature at which diesel fuel will still flow freely through a standard fuel filter without plugging. In practical terms, CFPP is the threshold where filter clogging becomes a serious concern. Typically, a diesel fuel’s CFPP is a few degrees below its cloud point (often about 3–5 °F lower than the cloud point for untreated fuel). For example, if a diesel’s cloud point is ~15 °F, its CFPP might be around ~10 °F. At the CFPP, wax crystals accumulate enough to starve the engine of fuel by clogging the filter. Think of CFPP as the “operational limit” in cold weather. Below that temperature, the engine likely stalls or fails to start from fuel starvation. Fuel additives that lower the CFPP are extremely valuable for winter operation (more on additives soon).
• Pour Point (PP): The pour point is essentially the gel point – the lowest temperature at which the fuel will still pour or flow. Below the pour point, the diesel fuel has solidified into a gel and will no longer flow at all. At this stage, the fuel in the tank is more or less frozen; if you tipped a container of the fuel, nothing would come out. Pour point is usually a few degrees below the CFPP. In many #2 diesels the pour point might be around 0 °F or a bit below (−18 °C), but again it varies depending on the blend. When fuel reaches pour point, the engine is completely inoperable until the fuel is warmed.

These temperature points can differ based on fuel formulation. #1 diesel (a lighter, kerosene-like fuel) has far less wax and thus a much lower cloud/pour point (it can stay liquid to –40 °F or below). #2 diesel (normal on-road diesel) has more paraffin; its cloud point can range anywhere from about –18 °F up to +20 °F depending on how it’s refined and whether it’s winter-treated. Blended winter diesel or additives can lower these points. Always remember that diesel’s cold flow characteristics depend on the exact blend of fuel you have. As a general rule, if temperatures approach the teens (°F), it’s time to take precautions, because you’re nearing typical cloud and filter plug points.

How Cold Does It Have To Be For Diesel To Gel?

It depends on the diesel fuel blend and quality, but diesel gelling typically occurs at around 15 °F (−9 °C) and below. At this point, so much wax has solidified that the fuel essentially freezes. If you are experiencing fuel problems at temperatures above ~15 °F (−9 °C), it’s likely not true gelling yet but another issue, such as water freezing, which we’ll cover later in this article. However, even before full gelling occurs, wax crystals can start causing trouble at higher temperatures as they form and bind together.

The root cause of diesel gelling is the fuel’s paraffin wax content. Under normal temperatures, the wax is dissolved in the diesel and poses no issue. In fact, it helps with fuel lubricity and energy content. But as the fuel cools, it eventually hits a temperature where the wax crystallizes. Think of how warm candle wax is liquid but turns solid when it cools – diesel wax behaves similarly. As temperatures drop:

• Wax crystals form and grow: Initially, tiny wax crystals start forming (around the cloud point). The fuel starts to look murky as millions of microscopic wax particles reflect light.
• Crystals cluster and restrict flow: With further cooling, those wax crystals bind together into larger flat, plate-like crystals that can plug filters and gather in low points of the fuel system. Fuel flow through hoses and filters becomes sluggish. This is when you hit the CFPP and the engine may struggle or lose power.
• Fuel solidifies: Finally, at a very low temperature, so much wax has solidified that the entire volume of fuel turns gel-like (the pour point). At this stage, fuel lines may be filled with a solid or gelled mass of waxy fuel that a pump cannot push through. The engine is effectively fuel-starved until the fuel is warmed up again.

Several factors influence what temperature your diesel will start to gel:

• Fuel Type and Blend: Standard #2 diesel contains the most wax and is the most prone to gelling. #1 Diesel, which is often used in winter blends, has less wax and a much lower gel point. Many fuel distributors sell “winter blend” diesel, which is typically a mixture of #2 and #1 diesel or #2 treated with additives, to lower the cloud and pour points for cold climates. If you are running on straight #2 summer diesel in frigid weather, it will gel much sooner than a winterized fuel. For example, #2 diesel might gel around 15 °F, whereas an 80/20 winter blend (80% #2, 20% #1) might be good down to 0 °F or lower.
• Fuel Quality and Additives: The amount of naturally occurring wax and other components can vary by batch and supplier. Low-quality or summer-grade diesel can have a higher cloud point (even above 32 °F in worst cases). High-quality winterized diesel will have additives or blending to reduce wax crystal formation. If you fuel up somewhere that doesn’t treat winter fuel adequately, your fuel could gel sooner.
• Biodiesel Content: Biodiesel (fuel made from vegetable oils or animal fats, often blended into diesel) tends to gel at higher temperatures than petroleum diesel. For instance, pure soybean B100 biodiesel can start to cloud around 34 °F (1 °C) – barely above freezing! A B20 blend (20% biodiesel) has a lower cloud point than B100 but still higher than pure petroleum diesel. In short, fuels with higher biodiesel percentages are more prone to cold flow issues, and may require additional additives or precautions in winter. If you use biodiesel blends, be aware of their higher gel point and treat the fuel accordingly.
• Water and Ice (Fuel Icing): Water contamination in diesel doesn’t cause wax gelling, but it can mimic the same outcome by forming ice crystals that block fuel flow. Even a small amount of water in diesel will freeze at 32 °F (0 °C) – much higher than diesel’s wax gel point. Often, the first problem diesel operators encounter in cold weather isn’t wax gelling at all, but ice in fuel lines or filters. Condensed water in your tank or water that naturally separates from ULSD fuel can turn into ice chunks that clog filters before the fuel itself ever clouds. We’ll talk more about distinguishing icing vs gelling in the next section, but it’s important to note here that keeping water out of your fuel is critical for winter reliability (since ice can plug things up even at temperatures where diesel wax is still liquid).

In summary, diesel fuel gels because paraffin wax solidifies in the cold, a process influenced by the fuel’s blend, quality, and contaminants. Next, we’ll look at how to tell true gelling apart from other cold-related fuel issues like icing.

Diesel Gelling vs. Fuel Icing (Wax vs. Water Problems)

It’s easy to shout “my diesel gelled!” when a truck won’t start on a winter morning, but the culprit might actually be ice rather than wax depending on the temperature. Both wax gelling and water icing can produce similar symptoms (engine sputtering or not starting), so it’s important to tell them apart for proper treatment. Here’s how to distinguish gelling vs. icing:

• Temperature clues: Actual wax gelling tends to occur at extremely cold temperatures (below ~10–15 °F). If your issues are happening in more moderate cold (say 20–30 °F), fuel icing is more likely the cause than wax gelling. In other words, a diesel engine that dies at 25 °F probably has a frozen water problem, whereas at 0 °F it could very well be wax gelling (or both).
• Inspecting the fuel filter: The fuel filter can reveal what’s blocking your fuel flow. Remove the filter (if possible safely) and look at the material clogging it:
• Ice will appear as white or clear ice crystals, which melt into water as they warm.
• Wax from gelled diesel looks thick, opaque, and waxy or oily. It’s often described as a thick, syrupy coating on the filter element. Wax may be whitish or yellowish and will soften into an oily substance when warmed (not just disappear like water). Sometimes gelled wax in a filter looks like petroleum jelly or paraffin coating the element. If you see obvious ice crystals, you had water in the fuel that froze. If you see a sticky wax coating, that’s diesel gel. For a quick test, bringing the filter into a warm area will melt ice into liquid water, whereas wax will merely soften and melt into diesel.
• Symptoms and timing: An engine affected by icing often sputters as ice clogs the flow, and the problem might come on suddenly right at the freezing mark. Wax gelling tends to be a gradual loss of power as fuel thickens, often after prolonged exposure to sub-zero temps. Also, if you get the engine started and warmed up an ice blockage may melt and the engine might run fine again until it cools and refreezes. Wax gelling won’t resolve itself until the fuel is heated significantly (or treated with additives).

Both issues can actually occur together in cold temperatures, but water is usually the first troublemaker in moderately cold weather. Modern Ultra-Low Sulfur Diesel (ULSD) fuel is actually more prone to water issues than older high-sulfur diesel, because removing sulfur also removed some natural solvency that kept water dispersed. ULSD and biodiesel blends tend to hold more water or allow more condensation, so icing has become a common winter diesel problem in recent years. This is why fuel water separators on diesel vehicles are so important: you should drain them regularly, especially before winter.

Preventing icing involves keeping water out of your fuel: drain water separators and tanks, keep tanks full to reduce condensation, and consider a fuel additive that handles moisture. The best diesel fuel additives, like Howes Diesel Treat, demulsify water without using harmful alcohols or solvents.

To summarize, it’s important to know your enemy. If it’s not extremely cold, but your diesel won’t run, suspect ice in the fuel. If it’s very cold and you see waxy fuel, suspect gelling. Either way, the solutions overlap: remove water, treat the fuel, and apply heat. We’ll cover specific prevention steps next.

How To Prevent Diesel Fuel Gelling

It’s far better to prevent fuel gelling (and icing) than to deal with a gelled-up truck at 6 AM in a blizzard. Fortunately, there are several effective strategies to keep diesel flowing in winter, ranging from buying the right fuel to using additives and taking care of storage. This section breaks down the best practices:

1. Add Anti-Gel Diesel Fuel Additives

One of the most popular and effective tools for preventing gelling is a diesel anti-gel additive (also called a cold flow improver or winter diesel treatment). These additives are chemical formulations designed to modify the wax crystals as they form, keeping them small enough to pass through filters, and to lower the fuel’s pour point and CFPP so that it remains usable at lower temperatures.

Here’s how anti-gel additives help combat gelling:

• Lowering the Wax Formation Temperature: Additives contain chemicals (such as proprietary polymers) that interfere with the wax crystallization process, effectively reducing the fuel’s cloud point. By dissolving into the fuel, they can break up the wax structure so that crystals form at a lower temperature than usual. For instance, a good winter additive might lower the cloud point by 10°F or more, meaning wax crystals won’t start forming until the fuel is that much colder.
• Keeping Wax Crystals Small (Cold Flow Improvers): Even when wax does crystallize, additives can prevent those crystals from bonding into large platelets. Cold Flow Improver (CFI) components in the additive change the shape of wax crystals and limit their size, so the fuel stays flowable. The wax remains as tiny dispersed particles that can slip through the filter instead of clogging it. Essentially, CFIs turn what would have been a big filter-clogging flake of wax into a multitude of microcrystals suspended in the fuel. This extends the Cold Filter Plugging Point much lower. In fact, treated fuel might not clog filters until 20–25 °F below its original cloud point, compared to only ~3–5°F below for untreated fuel.
• Other Benefits: Many winter additives pack additional benefits: lubricity enhancers (important because modern ULSD fuel is dry), and water demulsifiers (to address moisture). The popular Howes Diesel Treat formula prevents gelling and safely removes water, while containing no harmful alcohols or solvents.

It’s important to use an anti-gel additive before fuel temperatures drop. Pouring a regular anti-gel diesel additive into already gelled or cloudy fuel can’t dissolve big wax crystals that have already formed (though there are other products, such as Diesel Lifeline, that are formulated for that purpose.)

The best method is to treat your diesel fuel when refueling. The circulation from adding it during a fill-up helps mix it thoroughly. It’s wise to start using an anti-gel in the late fall or sooner if weather gets unexpectedly cold early, and continue with every fill-up through winter. Many experienced diesel owners will treat every tank once temperatures start getting below 30 °F in the mornings and evenings as cheap insurance.

Each product has a recommended treat rate (e.g. X ounces per gallons). This may vary depending on how cold it is. For example, Diesel Treat suggests 1 oz per 5 gallons in milder cold (above 0°F) but doubling to 1 oz per 2.5 gallons in extreme subzero temps. Always read the instructions for your specific additive and do not under-treat (adding a bit extra in severe cold is usually safe with reputable additives.

In short, a good anti-gel additive is one of the best tools to prevent diesel gelling. They are inexpensive and easy to use. Just remember: add before the cold hits. Think of it like antifreeze for your fuel.

2. Use Winterized or Blended Diesel Fuel

When you fill up at the fuel station, buy diesel that’s formulated for winter. During cold months, many fuel retailers (especially in colder regions) sell winter blend diesel, usually a mixture of #2 and #1 diesel, or #2 treated with cold-flow additives. Winterized fuels have a lower cloud point and gel point. For example, a typical winter blend might be 80% #2 and 20% #1, which can keep fuel operable to significantly lower temperatures than straight #2.

Note that while #1 diesel gels at a lower temperature, it is significantly lacking in lubricity and has lower energy content compared to #2 diesel, which can harm your engine and decrease power and fuel economy. Even when running winter blend diesel, it is still recommended to treat with an anti-gel and conditioner diesel fuel additive.

3. Keep the Engine and Fuel System Warm

Another straightforward approach to avoid gelling is to keep your fuel above its freezing point using heat or insulation. This can be part of your routine or a backup plan during cold snaps:

• Park Indoors or Use Engine Block Heaters: Whenever possible, park vehicles in a heated garage overnight to shield them from extreme cold. If indoor storage isn’t available, an engine block heater is invaluable. Block heaters plug into an AC outlet and keep the engine (and by proximity, the fuel in the engine and filters) warmer. Warm engines start easier and circulate warmer fuel back to the tank. Block heaters should be turned on a few hours before startup (or use a timer). In very harsh climates, diesel owners might leave block heaters on whenever the vehicle is parked for long periods.
• Insulation and Other Tricks: Simply insulating fuel filters and lines can delay freezing. There are inexpensive insulating wraps for fuel filter housings that help retain heat. Note that vehicle designs vary with some manufacturers placing fuel lines closer to points of exposure.
• Avoiding wind chill: Note that wind chill doesn’t directly cool fuel further than ambient temperature, but wind can accelerate how fast heat is drawn out of your equipment. Shielding vehicles from wind (parking behind a windbreak or using grill covers) can help keep under-hood temps slightly higher. Rely on actual air temperature (not wind chill factor) when gauging your anti-gel needs.

Using heat and shelter essentially buys you a margin if your fuel is near its cloud point. For instance, if it’s -10 °F outside but your truck was kept in a +40 °F garage, the fuel may never drop to its gel point before you start the engine and get it circulating. Of course, once you’re out and about, the fuel will cool, so combine this tip with adequate additives. Still, prevention measures like a block heater can mean the difference between a truck that starts in the morning and one that cranks but won’t fire due to gelled fuel.

4. Proper Fuel Storage and Maintenance (Keep It Dry and Clean)

How you store and handle diesel fuel can significantly affect its winter performance. Consider these practices:

• Keep tanks full: Whether it’s the vehicle’s fuel tank or a bulk storage tank, try to maintain a fuller tank in winter. A mostly empty tank has a lot of air space, which allows moist air to condense into water droplets as temperatures fluctuate. By keeping tanks topped off, you minimize air and condensation, thus reducing water accumulation (and the risk of icing). This also slows the fuel’s cooling (more volume cools slower).
• Drain water and sediment: Diesel tanks often have drains or water separators at the bottom. Before winter, drain any accumulated water from storage tanks and vehicle fuel filters/water separators. It’s much easier to remove water in liquid form than to deal with it as ice chunks in your fuel system. If your vehicle has a replaceable bowl or element fuel filter, replacing it before winter ensures you start with a clean, water-free filter (and carry spares – a partially clogged filter will be the first to gel up). Some filters and diesel fuel additives (demulsifiers) help remove water so it gets caught in separators.
• Regular filter changes: As part of winter prep, change your fuel filters (both primary and secondary, if applicable). A fresh filter gives maximum flow margin. Old filters accumulate wax, dirt, and water over time. A clogged or dirty filter is more likely to contribute to gelling problems. Starting winter with clean filters and then monitoring them is a smart move.
• Fuel additives for storage: If you store diesel for extended periods (e.g., in a generator tank or bulk tank over the winter), use a winter diesel fuel additive on that stored fuel as well. The main point: stored diesel should be dry and treated for cold too; otherwise, the first draw from that tank in January might be full of wax and ice.
• Trustworthy fuel suppliers: Finally, ensure you’re buying fuel from a reliable source that supplies seasonally appropriate diesel. Fuel from high-volume truck stops in winter is more likely to be adequately winterized than fuel from a low-volume station that might still have summer fuel in its tanks when a cold snap hits. When in doubt, ask the supplier what the fuel’s cold filter plugging point or additive package is and treat with your own winter diesel additive as well.

By following these preventive measures you greatly increase the chances that your diesel will run trouble-free all winter. However, if despite your best efforts you encounter gelled fuel, the next section covers how to get things flowing again.

What to Do If Your Diesel Fuel Gels (Emergency Measures)

Sometimes mother nature throws a curveball (like an unexpected cold snap before you added additive, or a vehicle left out in extreme cold), and you end up with gelled fuel. The engine won’t start, fuel filters are plugged with wax, and you need to recover the situation. What can you do to fix gelled diesel? Here are the steps and remedies:

• If possible, get the vehicle (or fuel) into a warm environment: The sure-fire cure for gelled diesel is heat. If possible, move the vehicle to a heated garage or shop and allow it to warm up. Often, just raising the fuel temperature back above the cloud point will re-liquefy the wax. Of course, towing a large truck or tractor to a warm shop isn’t always feasible. It may take a few hours, but warming the fuel will eventually melt the wax crystals and restore flow. Once melted, the fuel should flow again – but be aware any wax that had settled might clog the filter again once you start up, so you may need to change the fuel filter after thawing.
• Use an emergency additive like Diesel Lifeline: There are special emergency anti-gel additives formulated to re-liquefy gelled fuel quickly. These products are different from the preventative anti-gels because they contain powerful chemicals to dissolve wax crystals and thaw ice. Beware of products that contain harmful alcohols and solvents which can be damaging to your diesel engine. If you have a bottle of such emergency treatment on hand, follow the instructions: typically you pour the product directly into the fuel filter (after removing the filter) to dissolve the wax there, and then  add a substantial amount (proportionally higher dose than the preventative additive) to the tank. These products can often turn gel back into liquid fuel in as little as 15 minutes without external heat, though they work faster if the ambient temperature isn’t brutally cold. Once treated, try to start the engine again.
• Replace or bypass the fuel filters: In many cases, you will need to replace the fuel filter(s) after a gelling incident. Even if you melt the wax, the filter media might be clogged with congealed wax and will plug again quickly. It’s good practice to carry a spare fuel filter in winter for this reason. Before restarting the engine, swap in a new filter if you can (fill it with clean diesel or additive to help prime). If you don’t have a spare filter immediately available, as a temporary measure you could bring the filter indoors to thaw or heat it with a hair dryer to melt wax (then put it back on). But a new filter is best because gelling can sometimes create varnish-like deposits. Many mechanics will say: after getting running, change the filter at the earliest opportunity to avoid residual wax causing issues.
• Once running, let it warm thoroughly: If you get the engine started after a gel-up, let it idle and warm up for an extended period. The warm return fuel from the engine will circulate back to the tank and help thaw any remaining gel in the tank and lines. Make sure the vehicle reaches full operating temperature. This also ensures that if any partially dissolved wax is still moving through, it gets fully melted or caught in the filter.
• Do not add gasoline or hot liquids, etc.: Avoid “folk remedies” like dumping gasoline into the diesel tank or pouring boiling water over components. Adding gasoline to diesel is dangerous and can damage fuel system components (not to mention create a fire hazard). Similarly, using a torch or open flame to heat a fuel tank or filter is extremely dangerous: never do this. If you must apply heat, stick to safe indirect methods (electric heaters, warm water packs, or moving the vehicle indoors). Patience and proper additives are safer than trying a risky quick fix.

If you follow these steps, you can often recover a gelled engine without permanent damage. Afterward, definitely take preventive measures to avoid a repeat. Treat the fuel at every fill-up with a winter additive like Howes Diesel Treat and ensure the fuel is suitable for the temperatures you’ll encounter.

Clean, Prevent, and Rescue

Diesel gelling is a challenge that comes with the territory of running diesel engines in cold climates. To quickly recap: Diesel contains wax that can crystallize in the cold, causing the fuel to become cloudy at the cloud point, start plugging filters at the CFPP, and eventually solidify at the pour point if it gets cold enough. Keeping your diesel flowing in winter requires understanding these concepts and being proactive.

If you don’t already run a summer diesel additive to add lubricity, boost power and MPG, and remove water, it is recommended to start running one in the fall to clean your fuel system and engine before winter. Diesel fuel additives like Howes Diesel Defender guarantee a minimum of a 5% improvement in fuel economy and add vital lubricity to your fuel. Diesel Defender also safely removes water to reduce any potential icing issues in your fuel lines when winter hits.

Then, before winter hits, start regularly treating your fuel with an anti-gel additive like Howes Diesel Treat. Using Diesel Treat at every fill-up before the cold hits ensures that your entire fuel system is treated and ready to go to prevent gelling on cold days. Using an anti-gel diesel additive from a trusted brand like Howes is one of the most effective ways to protect your engine in cold weather. Howes stands behind its product with a winter guarantee: if you properly treat your fuel and still experience gelling, they'll cover the cost of your tow. Their formula is safe for use in all diesel engines and contains no harmful alcohols or solvents, making it a smart, engine-friendly choice when temperatures drop.

Lastly, carry an emergency treatment like Diesel Lifeline and spare fuel filters. Keeping an emergency diesel de-gelling additive in your vehicle, plus tools and a spare fuel filter, ensures that if gelling does catch you off-guard you can address it on the spot and get moving again.

By implementing the prevention strategies outlined above, from using the right fuel and additives to maintaining your fuel system, you can largely avoid the nightmare of diesel gelling. The cost and effort to winterize fuel is minor compared to the cost of a tow, lost productivity, or repairs from a gelled-up engine. With proper care, your diesel engines will remain reliable workhorses even on those cold winter days.