Fully synthetic LIQUI MOLY specialty with a unique additive technology. The powerful MFC (Molecular Friction Control) technology prevents formation of deposits while simultaneously reducing frictional losses. The synergetic effect provides optimum wear protection even under tough operating conditions. Improved fuel consumption and increased engine life are some of the end results. The oils fluorescent green color is typical for the MFC formulation.

• Miscible With All Commercially Available Motor Oils
• Tested For Turbochargers And Catalytic Converters
• Excellent High And Low Temperature Behavior
• Instant Lubrication After Cold Start
• Outstanding Lubrication Reliability
• Outstanding Engine Cleanliness
• Friction And Wear Reducing
• Optimum Stability To Aging
• Excellent Wear Protection
• High Shear Stability

This Part Fits:

Royal Purple Duralec Ultra 15W-40 is a premium heavy-duty engine oil engineered for diesel engines operating under high-load, high-stress conditions. Formulated to meet the rigorous API CK-4 service category, this oil provides superior protection against wear, oxidation, and deposit formation while maintaining excellent shear stability in modern emissions-controlled engines.

This 5-gallon pail is designed for professional maintenance, offering high-strength film protection to prevent metal-to-metal contact. Its advanced additive chemistry effectively manages soot to prevent oil thickening and abrasive wear, ensuring consistent performance throughout extended drain intervals.

• Viscosity Grade: 15W-40
• API Service Category: CK-4 (also covers CJ-4, CI-4 Plus, CI-4, and CH-4)
• Exceptional oxidation stability for high-temperature resistance
• Advanced soot dispersancy to maintain engine cleanliness
• Protects against valve train wear and piston ring sticking
• Volume: 5 Gallons / 18.9 Liters

Fits select 1994-2026 vehicles including Ford F-250/F-350 Super Duty, Ram 2500/3500, Nissan Titan XD, and Chevrolet Express 2500/3500.

Royal Purple Duralec Ultra 10W-30 is a high-performance synthetic diesel motor oil engineered for heavy-duty applications ranging from over-the-road trucking and commuting to agriculture, construction, and mining. Formulated with Royal Purple's proprietary Synerlec additive technology, this oil provides up to 4X the film strength and lubricity of leading competitors, significantly reducing friction and engine heat. It is specifically designed to maximize protection in high-output diesel engines, including both modern Tier 4 and older generation powerplants.

This CK-4 rated oil improves engine cleanliness through advanced synthetic solvency, which targets and reduces deposits. Its 10W-30 viscosity profile ensures excellent cold-flow operation and immediate startup protection in low-temperature environments while maintaining superior wear protection that exceeds CK-4 requirements by up to 33%.

• Viscosity Grade: 10W-30
• Service Rating: API CK-4
• Volume: 5 Gallon Pail
• Synerlec Technology: Provides unsurpassed film strength and reduced metal-to-metal contact
• Wear Protection: Up to 33% better than standard CK-4 requirements
• Drain Intervals: Extended life up to 40% better than CK-4 requirements
• Engine Cleanliness: Reduced oil consumption and deposit formation

Royal Purple Duralec Super 10W30 is a high-performance synthetic diesel engine oil engineered for modern, emissions-compliant powerplants. Fits select 1994-2026 Ford F-250/F-350 Super Duty, Ram 2500/3500, Nissan TITAN XD, and Chevrolet Express models. Formulated to exceed API CK-4 requirements, this oil is fully compatible with 2007 and 2010 emissions hardware, including Diesel Particulate Filters (DPF), Catalytic Converters, Exhaust Gas Recirculation (EGR), and Selective Catalytic Reduction (SCR) systems using ultra-low sulfur diesel (ULSD).

This synthetic lubricant is built to maximize component longevity by providing exceptional resistance to thermal breakdown at high operating temperatures while maintaining superior pumpability during cold starts to minimize startup wear. Duralec Super is designed to safely extend drain intervals, improve fuel efficiency, and maintain engine cleanliness through advanced additive chemistry that will not harm seals.

• Viscosity: 10W30
• Service Rating: API-licensed CK-4
• Quantity: 5 Gallon Pail
• Emissions Compatibility: Safe for DPF, SCR, EGR, and Catalytic Converters
• Corrosion Protection: Superior protection against corrosive engine acids
• Wear Protection: Enhanced film strength to minimize metal-to-metal contact

Fits select 1986-2026 Acura, AM General, Aston Martin, BMW, Chevrolet, Dodge, Ford, Freightliner, and Honda vehicles.

Royal Purple Duralec Ultra is a high-performance synthetic motor oil engineered for rigorous on-road and off-road diesel applications. Formulated with proprietary Synerlec additive technology, it creates an exceptionally tough ionic bond with metal surfaces to provide unsurpassed film strength and lubricity—up to 4x more than leading competitors.

This advanced formula significantly reduces engine deposits and wear, maintaining internal cleanliness and extending component life. By improving cold-flow operation and reducing oil consumption, Duralec Ultra minimizes downtime and lowers the total cost of ownership for heavy-duty applications in commuting, trucking, agriculture, and construction.

• Viscosity: 15W-40
• Service Rating: API CK-4
• Volume: 1 Gallon
• Film Strength: Up to 4x higher than top competitors
• Wear Protection: Up to 33% better than CK-4 requirements
• Oil Life: Up to 40% better than CK-4 requirements
• Advanced Solvency: Reduces engine deposits and varnish
• Cold Start: Improved cold-flow and start-up protection

Fits select 2003-2026 Chevrolet, Dodge, Ford, GMC, Hummer, Jeep, Nissan, and Ram diesel vehicles.

Royal Purple Duralec Super is a high-performance synthetic engine oil engineered specifically for modern diesel engines requiring emissions-compliant lubricants. Formulated to meet API CK-4 standards, this 5W-40 oil is designed for 2007 and 2010 emissions equipment, including Diesel Particulate Filters (DPF), Catalytic Converters, Exhaust Gas Recirculation (EGR), and Selective Catalytic Reduction (SCR) systems using ultra-low sulfur diesel (ULSD) fuels.

This synthetic formula is designed to maximize component longevity and safely extend drain intervals while improving fuel efficiency. It provides exceptional resistance to high-temperature thermal breakdown and maintains excellent pumpability in low temperatures to minimize critical wear during cold-induced startups.

• API-licensed CK-4 diesel motor oil
• Superior wear and corrosion protection for internal components
• Fully compatible with modern emissions equipment (DPF, SCR, EGR)
• Formulated for high-temperature stability and low-temperature flow
• Reduces exhaust emissions and keeps engine internals clean
• Will not harm engine seals or gaskets
• Viscosity: 5W-40
• Volume: 1 Gallon

Fits select 1994-2026 AM General, Chevrolet, Dodge, Ford, Freightliner, Hummer, Nissan, and Ram heavy-duty diesel applications.

Royal Purple Duralec Ultra is a high-performance 10W-30 synthetic motor oil specifically engineered for high-output diesel engines. Formulated with proprietary Synerlec additive technology, this oil creates an exceptionally tough ionic bond with metal surfaces, providing up to 4X the film strength of leading competitors to prevent metal-to-metal contact during extreme loads.

This CK-4 rated oil is designed to reduce engine deposits and provide superior cold-flow operation for reliable start-up protection in rigorous on- and off-highway environments. It exceeds standard requirements to help reduce downtime and lower the total cost of ownership for heavy-duty fleets and personal trucks alike.

• Viscosity: 10W-30
• Service Class: API CK-4
• Volume: 1 Gallon
• Additive Technology: Proprietary Synerlec formula
• Wear Protection: Up to 33% better than CK-4 requirements
• Oil Life: Up to 40% better retention than CK-4 requirements
• Improved cold flow operation and start-up protection
• Reduced oil consumption in older generation engines

Fits select 2001-2026 Acura, Aston Martin, Chrysler, and Dodge vehicles.

Royal Purple HMX Premium Synthetic High Mileage motor oil is engineered with advanced Synerlec technology to provide exceptional film strength and friction reduction for aging engines. This high-performance lubricant creates an ionic attraction to internal metal components, maintaining a protective film on parts even when the engine is off to minimize critical start-up wear.

• Synerlec Additive Technology: Increases oil film toughness to reduce friction and mechanical heat for peak engine performance.
• Oxidation Resistance: Provides outstanding thermal stability to resist oil breakdown and safely extend drain intervals.
• Start-Up Protection: Ionic bond ensures a layer of oil remains on metal surfaces to prevent dry-start wear.
• Viscosity Grade: 5W-20
• Container Size: 1 Quart

Fits select 1989-2026 Acura, AM General, Aston Martin, Audi, and BMW vehicles.

Royal Purple High Performance 5W-30 motor oil is engineered to meet the extreme demands of modern gasoline direct injection (GDI) and turbocharged engines. As manufacturers shift toward smaller, high-output powerplants, the risk of low-speed pre-ignition (LSPI) and internal wear increases. This premium synthetic formula utilizes advanced additive chemistry to neutralize LSPI risks while maintaining critical film strength at high operating temperatures and loads.

The 6 gallon bag-in-box (BIB) packaging provides a high-volume solution for shops and enthusiasts, offering a more sustainable and space-efficient alternative to individual plastic quarts. The sealed bladder design prevents oil oxidation and ensures a clean, controlled pour for every service.

• LSPI Mitigation: Specifically formulated to prevent destructive low-speed pre-ignition events in GDI and turbocharged engines.
• Wear Protection: Enhanced additive technology forms a robust barrier to protect critical engine components like timing chains and valvetrains.
• Fuel Efficiency: Low-friction synthetic base stocks help optimize fuel economy without compromising engine longevity.
• Extreme Temperature Stability: 5W-30 multi-grade rating ensures rapid lubrication during cold starts and superior thermal resistance at high RPMs.
• Efficient Packaging: 6 gallon Bag-In-Box reduces plastic waste and simplifies storage and dispensing in professional environments.

Fits select 1994-2025 Aston Martin, BMW, Chrysler, Dodge, Freightliner, Infiniti, Jaguar, and Jeep models.

Royal Purple High Performance Euro Formula 0W-40 Synthetic Motor Oil is formulated with premium synthetic base stocks and advanced additive technology to meet the demanding requirements of European gasoline and light-duty diesel engines. This 6-gallon Bag-In-Box (BIB) packaging provides a high-volume, convenient solution for professional shops and enthusiasts, ensuring peak engine protection during severe operating conditions.

Engineered for superior oxidation stability and low volatility, this synthetic formula significantly reduces oil consumption between service intervals and provides excellent resistance to sludge and varnish deposits. It is recommended for turbocharged and direct injection engines, including those equipped with diesel particulate filters (DPF) and selective catalyst systems.

• Viscosity: 0W-40
• Container: 6 Gallon Bag-In-Box
• Cold-Start Performance: Superior low-temperature fluidity for rapid lubrication.
• Engine Protection: Advanced wear and corrosion protection for internal components.
• Fuel Efficiency: Optimized formulation to assist in maximizing MPG.
• System Compatibility: Safe for engines with turbochargers and diesel emissions equipment.