STP Fuel System Cleaner & Fuel Injector Additive — 12 fl oz Single-Tank, High-Concentration Detergents

STP 1 Tank Tune Up is a concentrated fuel system cleaner and fuel additive designed to deep-clean injectors, intake valves, and combustion chamber deposits in a single 12 fl oz treatment.

This concentrated formula from STP delivers the brand’s strongest cleaning blend for gasoline engines, engineered to survive high combustion temperatures and reach hard-to-clean areas across the fuel delivery and exhaust chain. One bottle treats a full tank to help remove build-up that can reduce efficiency, contribute to rough idling, or interfere with emissions components. It’s intended as routine maintenance or a pre-test tune-up; follow vehicle manufacturer recommendations and local regulations for emissions and service intervals.

How does this additive clean fuel injectors and intake valves?

The proprietary STP blend contains high-concentration detergents and thermal-stable agents that flow through the fuel system and into the combustion chamber, loosening varnish and carbon deposits. Because the formula is designed to withstand high temperatures, active ingredients remain effective through the intake, valves, and piston tops for deeper cleaning.

• High-concentration detergents for injector and port cleaning
• Thermally stable agents that survive combustion heat
• One 12 fl oz dose treats a full tank for a single-use clean

Will this product help my vehicle pass an emissions test?

STP 1 Tank Tune Up aims to reduce hydrocarbon emissions by cleaning components that affect combustion quality and catalytic converter function. By lowering deposit levels on oxygen sensors and improving fuel burn, it can assist vehicles in approaching cleaner running conditions, though results depend on vehicle age and condition.

• Helps reduce hydrocarbon emissions by addressing buildup
• Supports oxygen sensor performance and catalytic converter protection
• May improve chances of passing emissions testing when deposits are a contributing factor

How will this additive affect fuel economy and engine performance?

Removing deposits from injectors and intake areas can restore more even fuel spray and combustion, which often improves throttle response and fuel efficiency. Consumers typically use this as a maintenance step to return drivability closer to original factory performance.

• Targets fuel injectors, intake valves, cylinder heads, and piston tops
• Can improve fuel delivery consistency and combustion efficiency
• One bottle is formulated for a single-tank treatment to simplify application

How should I use STP 1 Tank Tune Up and when is it recommended?

Pour one 12 fl oz bottle into a full tank of gasoline before filling, then drive normally to allow the formula to circulate and clean the system. Use as part of routine maintenance or before emissions testing; frequency depends on driving conditions and manufacturer guidance.

• Use one bottle per full tank of gasoline
• Best applied before driving to circulate cleaning agents through the system
• Follow product label and vehicle manufacturer instructions for safe use

Who is this for? STP 1 Tank Tune Up is intended for drivers and vehicle maintainers who fuel gasoline engines and want a concentrated, single-dose solution to address injector and intake deposits. It’s suitable for passenger cars, light trucks, and SUVs as part of scheduled maintenance or a pre-test tune-up. Avoid use in diesel engines and consult your vehicle manual if unsure about additive compatibility.