10 Best Diesel Fuel Additives 2026 in the United States

The Red Line 60103 SI-1 Complete Fuel System Cleaner is a concentrated additive designed mainly to clean and protect fuel systems by removing deposits from injectors, carburetors, valves, and combustion chambers. It excels in detergency, efficiently cleaning nearly all buildup with just one 15-ounce bottle per tank.

While it’s highly rated for cleaning and preventing corrosion, this product is primarily formulated for gasoline engines, so it may not be specifically tailored for diesel fuel needs such as cetane number improvement or anti-gel properties, which are critical in diesel additives. It does help stabilize fuel and reduce gum and varnish, which supports fuel efficiency and engine performance.

There’s no clear indication that it improves lubricity or disperses water, both important for diesel engine health. The pack of 12 offers good value if frequent treatments are needed. This cleaner is best suited for users looking to maintain and improve their gasoline engine’s fuel system cleanliness rather than those needing comprehensive diesel-specific fuel additive features.

The Archoil AR6500 Diesel Treatment is a versatile additive designed to improve several aspects of diesel fuel performance. It increases cetane numbers by up to 8 points, helping engines start more easily and run smoother, especially with lower cetane rating fuels. It also enhances lubricity significantly (tested to 43%), which protects sensitive fuel system components like the CP4 pump from wear and extends their lifespan.

This additive features a powerful detergent package that cleans fuel injectors, restoring proper spray patterns and improving fuel economy and engine performance. Additionally, it supports diesel particulate filter (DPF) health by reducing deposit buildup and regeneration frequency, saving money on maintenance. It also helps keep turbochargers cleaner for better responsiveness and smoother acceleration.

The product comes in two 40 oz bottles, treating up to 800 gallons of diesel, making it convenient for regular use at each fill-up. It suits a wide range of diesel vehicles and equipment, from light-duty trucks to heavy machinery, and is especially beneficial for users aiming to improve engine efficiency, protect fuel system parts, and maintain emission components.

The Archoil AR6500 Diesel Treatment is designed to enhance the performance and protection of all types of diesel engines, from light-duty pickups to heavy-duty trucks. It improves the cetane number by up to 8 points, which helps engines ignite fuel faster and run more smoothly. This can lead to a more responsive drive and potentially better fuel economy. It also significantly boosts lubricity by 43%, protecting sensitive fuel system parts like injection pumps from wear. Another strong point is its powerful detergent action that cleans injector deposits, helping maintain efficient fuel spray and engine performance.

The additive supports diesel particulate filter (DPF) health by reducing soot build-up and regeneration needs, which can extend DPF life and reduce maintenance. It also helps keep turbos clean, contributing to consistent boost and smoother acceleration. The treatment ratio is straightforward—each 10 oz bottle treats 100 gallons, and the 4-pack treats 400 gallons, making dosing easy and convenient.

Archoil AR6500 is a strong all-around additive focusing on cetane boost, lubricity, and cleaning benefits, making it an excellent choice for those looking to enhance engine smoothness, protect fuel systems, and maintain emission controls.