Red Line SI-1 Complete Fuel System Cleaner 15 oz (2-Pack) — Cleans Injectors, Prevents Corrosion

Red Line SI-1 Complete Fuel System Cleaner is a concentrated fuel-additive treatment designed to clean injectors, carburetors, valves and combustion chamber deposits while helping prevent fuel-system corrosion.

Every drive exposes your fuel system to varnish, gum and deposit buildup that can reduce efficiency and throttle response. Red Line's SI-1 formula combines high- and low-temperature detergents with corrosion inhibitors and gasoline stabilizers to address those deposits, restore cleaner fuel flow and maintain system integrity. This listing covers the 15-ounce bottle sold as a convenient two-pack for treating multiple tanks or keeping a spare on hand.

How does SI-1 improve fuel system performance?

SI-1 attacks deposits that form on injectors, carburetor jets, intake valves and in combustion chambers, helping restore spray patterns and combustion consistency. Cleaner components promote more complete fuel burn and steadier throttle response without altering engine tuning.

• Breaks down carbon, varnish and gum deposits at various temperatures
• Restores injector spray and carburetor flow for smoother idle and acceleration
• Helps maintain consistent fuel metering across operating ranges

How do I use this 15-ounce bottle for best results?

One 15-ounce SI-1 bottle is formulated for a single full tank treatment in most passenger vehicles; add directly to the fuel before filling to ensure proper mixing. For severely contaminated systems, one treatment often provides significant improvement, but repeated use can enhance and maintain results.

• Add one bottle to an empty tank, then fill with gasoline to mix
• Use every 10,000–15,000 miles or as needed for maintenance
• For heavy buildup, follow with a second treatment or professional service if needed

Will SI-1 protect my fuel system from corrosion and fuel breakdown?

SI-1 includes corrosion inhibitors and stabilizers that help limit metal oxidation and slow the formation of gum and varnish during storage or short-term fuel aging. While it reduces common degradation pathways, it’s not a long-term substitute for recommended storage procedures or periodic maintenance.

• Contains additives to inhibit corrosion on fuel-system metals
• Improves gasoline stability to reduce gum and varnish over time
• Helps protect components during seasonal storage or infrequent use

Is SI-1 compatible with modern engine types and fuel blends?

SI-1 is formulated for use in gasoline engines and works with contemporary fuel formulations, including ethanol blends common in consumer fuel. It is safe for use with catalytic converters and other emission-control systems when used as directed.

• Designed for gasoline engines, including vehicles using ethanol-blended fuels
• Safe for catalytic converters and standard emission control devices when used properly
• Suitable for carbureted and fuel-injected systems

Who this product is for: Red Line SI-1 is aimed at vehicle owners, fleet managers and enthusiasts who want a concentrated, professional-grade cleaner to remove deposits, improve fuel-system consistency and help guard against corrosion. It’s a practical choice for routine maintenance, pre-storage treatment and occasional restoration of drivability without modifying engine hardware or fuel mapping.

Ingredients

60103 SI-1