Leaded race fuel contains tetraethyl lead, a chemical compound added to the fuel blend to increase octane rating and provide lubrication for engine valve seats. Lead was removed from street gasoline decades ago, but it remains legal and widely used in sanctioned racing because of the performance and protection benefits it provides in specific engine applications.
The lead in race fuel serves two distinct purposes. The first is octane enhancement. Lead is an effective knock suppressant that allows fuel blenders to reach octane ratings that would be difficult or expensive to achieve through hydrocarbon chemistry alone. The second is valve seat lubrication. Older engines and many purpose-built race engines use hardened steel valve seats that rely on lead deposits for protection against wear. Running unleaded fuel in those engines accelerates seat recession and shortens engine life.
Sunoco leaded race fuels span from 106 to 118 octane and cover a wide range of racing applications, from circle track and drag racing to road course, karting, and truck and tractor pulling.
The leaded race fuel lineup covers 106 to 118 octane, with each product engineered for a specific performance range and application. Find the right match for your engine below.
Maximum detonation resistance for sprint cars, late models, and the most demanding race builds. Two-year-plus shelf life with proper storage.
Extreme knock resistance for drag racing and high-boost forced induction applications. Also suited for road course, snowmobile, and truck and tractor pulling.
Built for boosted engines and high-output builds where long shelf life matters. Three-year-plus stability makes it ideal for volume buyers and intermittent schedules.
Purpose-formulated to handle the sudden pressure spikes nitrous systems generate. Three-year-plus shelf life with proper storage.
A broad-application 116 octane fuel covering asphalt oval, dirt oval, drag, road course, karting, and more.
Consistent detonation protection for circle track and drag engines through a full race night. Three-year-plus shelf life with proper storage.
The most versatile fuel in the leaded lineup, covering everything from asphalt oval and drag to karting, powersports, and vintage cars.
The entry point to Sunoco's leaded range, suited for moderate to high-compression engines across circle track, drag, road course, and vintage applications.
Leaded race fuel is required or preferred in three main categories of engines.
High-Compression Race Engines Engines built with compression ratios that push beyond the octane ceiling of unleaded race fuel need leaded fuel to prevent detonation. Sprint cars, late model dirt engines, top fuel-adjacent applications, and high-output naturally aspirated drag motors regularly require 112 to 118 octane leaded fuel to operate safely at peak tune.
Vintage and Muscle Car Engines Engines built before unleaded fuel became standard were designed with soft iron valve seats that depend on lead for lubrication. Running unleaded fuel in these engines causes valve seat recession over time. Leaded race fuel maintains proper valve seat protection and provides the octane ratings many high-compression vintage engines require.
Forced Induction and Nitrous Applications Supercharged, turbocharged, and nitrous-assisted engines generate sudden spikes in cylinder pressure that demand high octane protection. Many of these builds rely on leaded fuel not just for octane but for the chemical stability leaded blends provide under extreme combustion events.
From bracket racing to pro-level competition, explore fuels engineered for maximum power, consistent combustion, and the demands of full-throttle acceleration.
Explore how Sunoco's leaded lineup fits into the broader high octane picture and find the right octane level for your compression ratio and build.
Discover how Sunoco's Double Distilled™ process delivers the purity and batch-to-batch consistency that high-compression builds depend on.
Learn More About Leaded Fuel
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