STA-BIL In-Season Fuel System Treatment & Injector Cleaner 32 oz — Concentrated, Corrosion Protection

STA-BIL In-Season Fuel System Treatment & Injector Cleaner is a 32 oz concentrated additive that cleans fuel injectors and the entire fuel system while helping prevent corrosion and improve fuel efficiency.

This product restores and protects running engines by removing varnish, gum, and water from fuel lines, injectors, pumps, and tanks. The formula is the same as STA-BIL's previous 360° Protection—now packaged as In-Season Protection—and is designed for routine use during operating months to keep combustion efficient and internal parts free from deposits and rust.

How does this cleaner improve engine performance?

The treatment removes deposits that restrict fuel flow and disturb spray patterns, which can result in smoother idling, steadier throttle response, and more complete combustion. Cleaner injectors and lines help the engine use fuel more efficiently without requiring mechanical work.

• Removes gum, varnish, and deposits from injectors and lines
• Improves spray pattern for consistent combustion
• Reduces rough idle and hesitation caused by clogged parts
• Helps maintain engine power during normal operation

How does it protect against corrosion and water damage?

STA-BIL’s formula includes corrosion inhibitors that cling to metal surfaces inside the fuel system to resist rust formation. It also helps disperse water mixed with fuel so water does not pool and accelerate corrosion or damage internal components.

• Coats internal fuel system metals with rust inhibitors
• Breaks up and disperses small amounts of water in fuel
• Prevents tank and line corrosion over repeated treatments
• Compatible with modern fuels and typical fuel-system metals

How do I use this 32 oz bottle—what’s the dosage?

Pour the additive directly into the fuel tank before filling. The recommended ratio is 1 ounce per 5 gallons of fuel, so one 32 oz bottle treats up to 160 gallons. Use as a periodic in-season maintenance step or whenever fuel quality is questionable.

• Use 1 oz per 5 gallons of fuel (pour before filling)
• 32 oz treats up to 160 gallons—suitable for many top-ups
• Safe for regular in-season maintenance schedules
• Works with gasoline engines and standard fuel system components

Will this work year-round or only during operating months?

This product is formulated for in-season, operational protection—keep using it while equipment is in service to maintain clean injectors and corrosion protection. For long-term storage, pair it with STA-BIL Storage to prevent fuel breakdown during extended off-seasons.

• Designed primarily for active use periods to maintain performance
• Combine with STA-BIL Storage for winter or long-term storage protection
• Helps preserve fuel quality between service intervals
• Supports both performance and longevity of fuel-system parts

Who is this for: STA-BIL In-Season Fuel System Treatment & Injector Cleaner is ideal for car owners, truck drivers, small engine users, and fleet managers who want an easy preventive maintenance step. It suits anyone who refuels regularly and wants to reduce deposit buildup, guard internal parts from rust, and support efficient fuel use without mechanical intervention.