Understanding API in Engine Oils: A Complete Guide
When selecting engine oil, you’ll notice labels like API SP, SN, or CK-4 – but what do these codes actually mean? The American Petroleum Institute (API) classification system serves as the global benchmark for engine oil quality, ensuring lubricants meet the rigorous demands of modern engines. At Caretta, we engineer our oils in the Holland to not just meet but exceed these critical API standards, delivering optimal protection for your vehicle.
Decoding API Classifications
The API system uses a simple yet informative coding method:
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First letter indicates engine type:
• “S” (Service) = Gasoline engines (e.g., SP, SN, SM)
• “C” (Commercial) = Diesel engines (e.g., CK-4, CJ-4) -
Second letter reveals performance level (higher alphabet = newer/more advanced)
Current API Standards (2024)
For gasoline engines:
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API SP (2020): Advanced protection for turbocharged direct-injection engines
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API SN+ (2018): Enhanced prevention of low-speed pre-ignition
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API SN (2010): Suitable for most conventional gasoline vehicles
For diesel engines:
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API CK-4 (2016): High-performance protection for modern diesel engines
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API FA-4: Fuel-efficient low-viscosity options for newer diesel models
Why API Ratings Matter for Your Engine
Using oil with incorrect API specifications can lead to:
• Accelerated engine wear and component damage
• Reduced fuel efficiency and performance
• Increased sludge and deposit formation
• Potential harm to emission control systems
How to Select the Right API-Rated Oil
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Consult your vehicle’s owner manual for manufacturer recommendations
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Look for the API certification mark (the “donut” symbol) on oil containers
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When in doubt, choose the newest compatible API classification
Caretta’s Commitment to API Standards
Our Holland engineered oils are:
• Formulated to meet the latest API SP and CK-4 requirements
• Enhanced with advanced additives for superior wear protection
• Optimized for both performance and fuel efficiency
• Compatible with modern emission systems