10 Best Auto Fuel Additives 2025 in the United States

The Sea Foam SF128 Motor Treatment is a multi-purpose fuel additive that works effectively with both gas and diesel engines. It excels in dissolving and cleaning fuel deposits, preventing sticky residues from clogging injectors, carburetors, and combustion chambers. This makes it a good fit for those looking to maintain engine cleanliness and efficiency.

Another strong point is its ability to stabilize stored fuel for up to two years, which is particularly beneficial for vehicles that are not used frequently, like seasonal equipment or classic cars. Additionally, it provides high-temperature upper cylinder lubrication, protecting the fuel system from wear and corrosion.

A notable advantage is that it contains only petroleum-based ingredients, avoiding harsh detergents or chemicals that might harm the engine, with the added benefit that using more of the additive will enhance its cleaning effects. Sea Foam SF128 Motor Treatment is well-regarded for its comprehensive cleaning and protective capabilities, making it a reliable choice for anyone looking to maintain their vehicle's fuel system in top condition.

The Chevron Techron Concentrate Plus Fuel System Cleaner is a highly concentrated auto-fuel-additive that is designed specifically for gasoline engines. It comes in a 20 oz bottle, which is suitable for treating larger fuel tanks or providing multiple treatments for smaller tanks. This product is well-regarded, holding the #1 spot in fuel system cleaners and boasting a 4.6-star rating from over 15,000 customer reviews, showing strong brand reputation and user satisfaction. It targets common engine issues such as rough idling, engine surging, hesitation, and spark plug fouling, making it effective for maintaining smoother engine performance and improving cold start performance and fuel stability for up to a year.

This could be particularly beneficial for those experiencing these specific issues or looking to prevent them. The additive is easy to use as it is in liquid form and unscented, which makes handling it more pleasant. However, it is essential to follow the recommended dosage instructions to avoid overuse, which can be a common concern with concentrated formulas. Moreover, as it is specifically formulated for gasoline engines, it is not compatible with diesel engines, limiting its use in mixed-vehicle households. Despite this limitation, the Chevron Techron Concentrate Plus remains a strong contender for anyone seeking to improve their gasoline engine's performance and longevity.

The Lucas Oil 10003 Fuel Treatment is a versatile additive, suitable for both gasoline and diesel engines. It's designed to improve fuel economy, enhance power and acceleration, and clean the fuel system, including injectors and combustion chambers. The additive also helps neutralize sulfur and other contaminants, which can extend the life of your engine and its components.

It's particularly beneficial for those looking to maintain or improve the health of older engines, as it safely replaces the need for lead without causing harm. Additionally, it prevents rust and corrosion, aligning with federal low sulfur content requirements for diesel vehicles and equipment.

A standout feature is its ability to increase MPG and reduce exhaust emissions, making it a practical choice for regular engine maintenance. Lucas Oil is a reputable brand in the automotive industry, adding a level of trustworthiness to this product.