Fuel additives play an important role in maintaining engine health and efficiency. By cleaning deposits, stabilizing stored fuel, and improving combustion, they help vehicles run more smoothly and reliably. Whether used in everyday driving, seasonal equipment, or high-performance applications, these treatments can support longevity and reduce common issues. Exploring different options allows drivers to choose the best fit for their specific needs.

1. Lucas Oil Products Upper Cylinder Lube & Fuel Treatment – 5.25 oz

This treatment is designed to lubricate upper cylinders and improve fuel combustion efficiency. By adding a protective layer, it reduces wear on critical engine parts while helping fuel burn more thoroughly during operation.

It also works to minimize harmful deposits, support smoother engine performance, and extend the life of injectors and carburetors. Suitable for both gasoline and diesel systems, it provides balanced maintenance benefits.

Pros:

• Lubricates upper cylinder area

• Works in gas and diesel

• Reduces harmful deposit buildup

• Supports smoother performance

• Extends injector component life

Cons:

• Small 5.25 oz bottle

• Requires frequent reapplication

• Limited for long-term storage

• No octane-boosting properties

• Not specialized for ethanol

2. Red Line S-1 Fuel System Cleaner – 15 oz

This cleaner uses high concentrations of polyether amine (PEA) detergents to remove carbon deposits from injectors, valves, and combustion chambers. It is designed to restore fuel flow and help engines maintain reliable performance.

Regular use may improve throttle response and reduce emissions caused by buildup. Its formulation supports modern fuel systems and offers cleaning strength beyond many standard consumer additives.

Pros:

• Strong PEA cleaning formulation

• Targets valves and injectors

• Helps restore fuel efficiency

• Supports modern fuel systems

• Reduces carbon deposit buildup

Cons:

• Not for long-term storage

• Requires consistent use

• Higher price per ounce

• Limited impact on lubricity

• May need multiple treatments

3. STA-BIL Storage Fuel Stabilizer – 10 oz

This stabilizer keeps fuel fresh for up to 12 months, helping prevent gum, varnish, and corrosion during periods of vehicle or equipment storage. It protects internal engine components from degradation caused by aging fuel.

It works in all gasoline blends, including ethanol mixes, and helps engines start easily after extended downtime. It is often applied in seasonal vehicles such as boats, motorcycles, and lawn equipment.

Pros:

• Keeps fuel fresh long term

• Reduces corrosion and varnish

• Works with ethanol blends

• Assists seasonal equipment starts

• Protects engine internal parts

Cons:

• No direct cleaning effect

• Limited performance boosting

• Not useful in daily use

• Requires full tank mixing

• Strict dosing recommendations

4. Sea Foam Motor Treatment – 1 Gallon

This versatile formula works in both fuel and oil systems, cleaning deposits from injectors, carburetors, intake valves, and combustion chambers. It also helps stabilize fuel during storage while controlling moisture buildup.

In oil systems, it may quiet noisy lifters and dissolve sludge. Its gallon size offers economical treatment for multiple applications, covering a wide range of gasoline and diesel engines.

Pros:

• Works in fuel and oil

• Large gallon-sized container

• Cleans combustion deposits

• Helps stabilize stored fuel

• Reduces engine sludge buildup

Cons:

• Requires accurate measuring

• Higher upfront cost

• Not octane booster specific

• Needs repeated use for effect

• May thin older engine oil

5. FRAM Octane Booster – 12 oz

This additive raises fuel octane rating, which helps reduce engine knocking and pinging under heavy load or high-temperature operation. It is intended to provide smoother combustion and improved responsiveness.

The formulation is compatible with gasoline engines and works best in vehicles where detonation is a recurring issue. It offers a straightforward performance adjustment without altering other aspects of the fuel.

Pros:

• Raises fuel octane rating

• Reduces knocking and pinging

• Improves combustion stability

• Simple single-use formula

• Compatible with gasoline engines

Cons:

• No cleaning properties included

• Limited to performance correction

• Requires repeated use

• Not effective for ethanol wear

• Provides temporary benefit only