Red Line SI-1 Fuel System Cleaner 15 oz, 12-Pack — Concentrated Deposit Remover & Fuel Stabilizer

Red Line 60103 SI-1 is a concentrated 15-ounce fuel system cleaner designed to remove deposits and protect fuel-system components when used one bottle per tank.

Engine deposits in injectors, carburetors, valves and combustion chambers reduce efficiency and throttle response over time. Red Line SI-1 combines high- and low-temperature detergents in a single-treatment formula to clean these areas, improve fuel stability, and limit gum and varnish buildup. This listing is for a 12-pack of 15-ounce bottles, sized to treat multiple tanks or a fleet of vehicles.

How does Red Line SI-1 clean injectors and combustion chambers?

SI-1 uses a concentrated detergent chemistry that dissolves and disperses carbon, varnish, and gum from fuel system surfaces. When added to a full tank of gasoline, it moves through the fuel delivery system to break loose deposits and carry them through combustion and the exhaust system.

• Targets injector tips and spray patterns to restore atomization
• Loosens combustion chamber carbon for cleaner burn
• Formulated for both high-temperature and low-temperature deposits
• One 15-ounce bottle treats one full tank for near-complete cleaning

Will this improve fuel stability and reduce varnish?

Yes — SI-1 contains stabilizing agents that slow oxidation and degradation of gasoline, which helps prevent gum and varnish from forming during storage or regular use. Regular treatments reduce fuel breakdown that can cause sticky deposits on metal surfaces.

• Enhances gasoline stability during storage or infrequent use
• Minimizes new gum and varnish formation after treatment
• Suitable for seasonal storage or long idle periods

How do I use this product safely and effectively?

Use one 15-ounce bottle per full gasoline tank for most passenger cars and light trucks, pouring the contents into the fuel tank before refilling. Follow basic safety: avoid open flames, funnel spillage into approved containers, and store bottles upright in a cool, ventilated area.

• Pour one bottle into tank, then refuel immediately to mix
• Do not overuse — one bottle per tank delivers recommended concentration
• Store in original container away from heat and ignition sources

Is Red Line SI-1 compatible with all gasoline engines?

SI-1 is formulated for gasoline-powered engines including EFI (electronic fuel injection) and carbureted systems. It cleans across common fuel-system types without modifying engine hardware, but always check manufacturer guidance for specialized or warranty-sensitive equipment.

• Safe for EFI and carburetor-equipped gasoline engines
• Effective for older engines with heavy deposits and modern engines with precision injectors
• Not intended as an additive for diesel or other fuel types

Who is this for: Red Line 60103 SI-1 is aimed at vehicle owners, shop technicians, and fleet managers who want a concentrated, single-bottle treatment to restore fuel-system cleanliness and improve fuel stability. It's well-suited for routine maintenance, performance tuning prep, seasonal storage, and any situation where reducing deposits and maintaining consistent fuel behavior matters.