5 Most Effective Diesel Additives for Winter Weather
The colder the weather, the higher the risk that your diesel engine will not start. Extremely low temperatures can cause “diesel gelling,” which happens when the paraffin wax in the fuel solidifies into crystals and clogs the fuel lines and filters. Fortunately, you can avoid this problem by using additives that help keep your engine running smoothly throughout the winter.
How Were the Best Diesel Additives Evaluated?
Not all additives are created equal. Some have a comprehensive, high-performance formula, while others remove, emulsify or dissolve water. Here’s a detailed look at the criteria used to assess the heavy-duty diesel engine oil additives on this list.
| Criteria | Description |
| Anti-gel performance | The additive must effectively lower the cold filter plugging point (CFPP), which is the temperature at which wax crystals will block a fuel filter. It must offer a significant buffer against sudden temperature drops. |
| Cetane improvement | The higher the cetane number, the shorter the delay between fuel injection and ignition. Additives that can provide a cetane boost contribute to faster, easier and quieter starts, putting less strain on the battery and starter. |
| Lubricity | The additive must provide added lubrication to protect fuel injectors and pumps against wear from ultralow sulfur diesel (ULSD). |
| Water dispersal | The additive must be able to remove moisture from the fuel to prevent icing in the fuel system. |
| Overall value and reputation | The additive must combine the ideal treat rate, cost-effectiveness and reputation. |
What Is the Best Diesel Additive for Winter?
Investing in the right additive can help you avoid costly downtime, tow bills and service calls. Based on the above criteria, look for the best diesel additives for the colder months.
1. Hot Shot’s Secret EDT+ Winter Defense
Hot Shot’s Secret EDT+ Winter Defense is a premium, all-in-one winter solution for any diesel engine. It prevents fuel gelling down to -40° Fahrenheit by reducing the size of wax crystals and lowering the Cold Filter Plugging Point (CFPP), ensuring reliable fuel flow in extreme cold. It also boosts cetane for improved combustion and cold starts, while enhancing lubricity with LX4 to protect fuel system components from wear.
This 7-in-1 formula includes a keep-clean detergent package, de-icer chemicals to disperse moisture and prevent icing, and a corrosion inhibitor to protect metal surfaces. EDT+ Winter Defense is available in 6-ounce, 8-ounce, 16-ounce squeeze bottles, 1-quart, 1-gallon, and 5-gallon sizes. A 6-ounce bottle treats up to 25 gallons of diesel fuel.
Hot Shot’s Secret develops solutions to address specific, challenging vehicle problems. It first became known for solving the notorious fuel injector issues in Ford Powerstroke engines, highlighting its understanding of what high-performance engines need. EDT+ Winter Defense builds on that legacy with a comprehensive formula tailored for cold-weather diesel performance.
2. Power Service Diesel Fuel Supplement + Cetane Boost
Power Service Diesel Fuel Supplement + Cetane Boost is one of the most recognized heavy-duty diesel engine oil additives on the market. Nearly every truck stop and auto parts store sells it, which is a significant advantage if you need to stock up.
This formula can lower diesel CFPP by as much as 36° Fahrenheit. It has a proven track record of preventing fuel gelling and icing and boosting cetane to improve cold-weather performance. The fuel supplement product also increases lubricity to protect the fuel system. Its availability and cost-effectiveness make it a go-to for vehicle owners and large fleet managers.
The Power Service Diesel Fuel Supplement + Cetane Boost is available in a wide range of quantities, from 12-ounce bottles to 260-gallon totes and bulk. Each product comes with detailed instructions about the additive-to-diesel ratio treatment.
3. Lucas Oil Anti-Gel Cold Weather Diesel Treatment
Lucas Oil Anti-Gel Cold Weather Diesel Treatment is one of the best oil additives for diesel engines during the colder months. One quart of this formula treats 150 gallons of fuel, lowering its CFPP by up to 10° Fahrenheit and preventing diesel from thickening and gelling. It works for all diesel fuels, including ULSD and biofuels.
Lucas Oil is a renowned brand for its high-quality lubricants and additives. Its anti-gel formula is alcohol-free, which means it won’t dry out seals or damage sensitive fuel system parts and is compatible with modern diesel engines. A quart of Lucas anti-gel can treat 150 gallons of ULSD fuel, but you may need an additional bottle if operating in freezing temperatures.
4. AMSOIL Diesel 4-in-1 Fuel Additive
AMSOIL Diesel 4-in-1 Fuel Additive is one of the best diesel additives on the market because it combines the benefits of multiple additives in a single formula. It improves year-round performance, including in the colder winter months. It can lower diesel’s CFPP by up to 40° Fahrenheit and improve cetane by up to four points. The formula also boosts lubricity, cleans dirty injectors and prevents wax settling.
This additive is alcohol-free, making it safe for sensitive components and compatible with modern emissions systems. An ounce can treat up to 2.5 gallons of diesel. AMSOIL’s 4-in-1 formula is a great choice for anyone seeking a single product that meets all their additive needs.
5. Howes Diesel Treat
Howes Diesel Treat is known for its “no-gel” guarantee. If your fuel gels up while using this formula correctly, Howes will pay for the tow service. This additive is preferred by those who want to actively remove water from their fuel system because it acts as a demulsifier. Unlike emulsifiers, which suspend water in the fuel, demulsifiers separate water from the fuel, effectively preventing fuel line freeze-ups.
This diesel additive for winter can lower CFPP by up to 20° Fahrenheit. This formula doesn’t boost cetane, but it naturally improves the combustion quality of diesel fuel.
The amount of diesel Howes Diesel Treat can treat depends on the temperature. For example, if it’s below 0° Fahrenheit outside, the ratio would be 1 ounce of the formula per 2.5 gallons of diesel. Once the temperature rises, you can use 1 ounce of Diesel Treat per 5 gallons of fuel.
Drive Confidently Through the Cold With the Best Diesel Fuel Additive
Fuel gelling is preventable with the right diesel fuel additives, so be sure to examine your options. Compare their anti-gel protection, cetane number boost, fuel system lubricity and demulsifiers. When in doubt, ask your trusted mechanic for their recommendations based on your vehicle and the area’s condition. Take proactive steps to protect your engine and ensure it continues to function properly throughout the season.
*Please note that this list includes sponsored content. Some of the companies, products, or services featured have entered into commercial agreements for placement. Sponsored placements do not necessarily reflect an endorsement and should be considered alongside other options in the marketplace.