FAQ

Engine Oil Composition

Engine oil is a highly complex formulation designed to protect and enhance engine performance. It is primarily composed of base oils (approximately 75% to 90%) and performance additives (about 10% to 25%). Each component serves a specific function to meet the demanding requirements of modern engines.

Base Oils (75%-90%): The base oil forms the majority of engine oil and determines its fundamental properties such as viscosity, volatility, and oxidative stability. High-quality base oils contribute to better engine cleanliness and durability.

Additives (10%-25%): Performance additives are engineered chemicals that enhance or introduce specific oil characteristics. Common types include:

• Detergents: Maintain engine cleanliness by neutralizing acids and preventing deposits
• Dispersants: Suspend contaminants in oil, preventing sludge and varnish formation
• Antioxidants: Slow down the oxidation process to extend oil life
• Anti-wear agents: Form protective films to minimize metal-to-metal contact
• Extreme pressure additives: Protect under high load conditions
• Friction modifiers: Improve fuel economy by reducing internal friction
• Anti-foam agents: Prevent foam formation which can impair lubrication
• Corrosion inhibitors: Prevent rust and corrosion on metal surfaces
• Pour point depressants: Improve low-temperature flow performance

Engine Oil Viscosity & Classification

Engine oil viscosity refers to the oil's resistance to flow and is one of the most critical properties for engine protection and efficiency.

Viscosity Grades: Expressed in numbers like 0W-20, 5W-30, or 10W-40.

• The number before the 'W' (e.g., 0W, 5W) indicates the oil's low-temperature (winter) performance. A lower number means better flow at cold temperatures
• The number after the 'W' (e.g., 20, 30, 40) represents the oil's viscosity at high operating temperatures (100°C). Higher numbers indicate thicker oils suited for higher temperature or severe conditions

Multigrade Oils: Modern engine oils are typically multigrade, meaning they are designed to perform well in both cold starts and high-temperature conditions. For example, 5W-30 oil flows well in cold conditions and maintains sufficient thickness when hot.

Base Oil Categories (API Classification)

Base oils are the foundation of engine lubricants and significantly influence their overall performance. The American Petroleum Institute (API) classifies base oils into five categories based on their composition and refining methods.

API Viscosity Standards: The American Petroleum Institute (API) sets viscosity and performance standards for engine oils. These standards ensure compatibility and protection for gasoline and diesel engines.

Selection Principle:

• Always follow the vehicle manufacturer's recommendation for viscosity grade
• For older engines with higher mileage, a higher viscosity oil (e.g., 10W-40) may provide better sealing and protection
• For extremely cold climates, use oils with lower 'W' grades (e.g., 0W-20 or 5W-30) for improved cold start protection

Group I: Less than 90% saturates, more than 0.03% sulfur, and viscosity index between 80-120. Produced primarily through solvent refining processes. Basic performance and used in older-generation lubricants.

Group II: More than 90% saturates, less than 0.03% sulfur, and viscosity index between 80-120. Made using hydrocracking, providing better oxidation stability and fewer impurities than Group I. Widely used in modern engine oils.

Group III: More than 90% saturates, less than 0.03% sulfur, and viscosity index above 120. Fully hydrocracked and often referred to as 'synthetic' in the market. Offers superior oxidative stability and low volatility.

Group IV: Composed of Polyalphaolefins (PAO), which are synthetic hydrocarbons. Engineered molecules with uniform structure and high viscosity index (>140). Excellent low-temperature performance and thermal stability.

Group V: Includes all other base oils not in Groups I-IV, such as esters, naphthenics, silicones, and PAGs. Commonly used in combination with other groups to enhance performance. Synthetic esters are widely used in high-performance and racing oils due to excellent thermal resistance and polarity.

Base Oil Manufacturing Process

Base oil manufacturing involves either refining crude oil or synthesizing molecules through chemical processes. The type of processing significantly impacts the purity and performance of the final base oil.

Mineral Base Oil Production:

• Derived directly from crude oil through physical and chemical refining processes
• Atmospheric and vacuum distillation: Separates crude oil into fractions
• Solvent deasphalting: Removes heavy asphaltenes and residues
• Solvent refining: Enhances base oil quality by removing aromatics and impurities
• Solvent dewaxing: Improves low-temperature fluidity
• Clay treatment or hydrofinishing: Further purifies and stabilizes the base oil

Synthetic Base Oil Production:

• Involves chemical synthesis rather than simple distillation
• PAO (Polyalphaolefin): Made from ethylene oligomerization
• Synthetic esters: Produced from carboxylic acids and alcohols
• Others: Polyalkylene glycols (PAGs), silicones, phosphate esters
• Offers greater molecular uniformity and customized performance properties

Comparison:

• Mineral oils are mixtures of naturally occurring hydrocarbons with variable molecule sizes
• Synthetic oils feature engineered, uniform molecules, resulting in superior lubrication, stability, and low-temperature performance

Additives and Their Functions

Lubricant additives are essential performance-enhancing components that significantly improve oil properties and enable it to meet modern engine requirements. Though additives make up only 10%-25% of the oil, they play a crucial role in protecting engine components.

Key Additive Types and Their Functions:

• Detergents: Clean engine surfaces by neutralizing acids and preventing deposit formation; maintain piston cleanliness and reduce high-temperature carbon buildup
• Dispersants: Keep soot, sludge, and other contaminants suspended in the oil; work synergistically with detergents to prevent deposit formation
• Antioxidants: Prevent oxidation of the oil, which can lead to thickening and deposit formation; extend oil life and improve thermal stability
• Anti-Wear Agents: Form a protective film on metal surfaces to reduce friction and wear; especially important in high-load areas like camshafts and valve trains
• Friction Modifiers: Reduce internal engine friction to enhance fuel efficiency; commonly used in low-viscosity and fuel-efficient engine oils
• Extreme Pressure (EP) Additives: Provide enhanced protection under high load and metal-to-metal contact; common in gear oils and high-performance applications
• Anti-Foam Agents: Inhibit foam formation to ensure consistent oil circulation and lubrication
• Corrosion Inhibitors: Protect engine metals from rust and chemical degradation
• Pour Point Depressants: Enhance low-temperature fluidity by lowering the oil's pour point

Modern lubricants are carefully balanced blends of these additives to achieve optimal protection, cleanliness, and efficiency for both gasoline and diesel engines.

Oil Specification & Application Guidelines

Selecting the right engine oil is critical for ensuring long-term engine performance, reliability, and compliance with OEM standards.

General Selection Guidelines:

• Always consult the vehicle owner's manual for the recommended oil specification and viscosity grade
• Use engine oil that meets or exceeds the manufacturer's quality standards (API, ILSAC, ACEA)

Quality Grade Selection:

• Choose a quality grade that matches or exceeds the OEM specification
• For gasoline engines, refer to API 'S' series ratings (e.g., SN, SP). Higher letters mean newer and more advanced standards

Viscosity Grade Selection:

• Maintain the specified viscosity recommended by the engine manufacturer
• For older engines with higher mileage and increased internal clearance, a higher viscosity oil (e.g., 10W-40 or 15W-40) may be preferable
• For cold climates, opt for lower 'W' grade oils (e.g., 0W-20 or 5W-30) to ensure smooth cold starts

Hybrid Engine Oils: Hybrid engines often utilize Atkinson cycle technology and have unique lubrication requirements. Use fully synthetic low-viscosity oils (e.g., 0W-20, 0W-16) for better fuel efficiency and reduced friction.

Turbocharged & GDI Engines: Require oils with strong protection against oxidation, LSPI (Low-Speed Pre-Ignition), and wear. Recommended oils: API SN PLUS or SP with ACEA C2, C3, or C5 specifications.

Vehicles with GPF (Gasoline Particulate Filter): Use low-SAPS oils that reduce ash content to avoid clogging the GPF. Look for API SP and ACEA C-series (e.g., C2, C3, C5) oils.

Summary: Matching the right oil specification with your engine type and operating environment ensures optimal performance, reduced emissions, and longer engine life.

Industry Standards Explained

Engine oil standards ensure that lubricants meet specific performance, compatibility, and durability requirements defined by global automotive and petroleum organizations.

API (American Petroleum Institute):

• The API classifies engine oils primarily for gasoline and diesel engines
• 'S' series (e.g., SN, SP) is for gasoline engines; 'C' series (e.g., CK-4) for diesel engines
• The latest specification, API SP, offers enhanced protection against wear, oxidation, and LSPI (Low-Speed Pre-Ignition)
• API SP is backward compatible with previous categories (except SP 0W-16)

ILSAC (International Lubricants Standardization and Approval Committee):

• Jointly established by Japanese and American automakers (JAMA & AAMA)
• ILSAC standards (GF-1 to GF-6) add fuel economy and emission system compatibility requirements to the API standards
• GF-6A: For XW-20 and XW-30 oils; backward compatible with GF-5
• GF-6B: For 0W-16 oils; not backward compatible

ACEA (European Automobile Manufacturers' Association):

• Defines oil standards for European gasoline and diesel engines
• A/B: For gasoline and light-duty diesel engines
• C: Low-SAPS oils for engines with after-treatment systems (GPF, DPF, TWC)
• E: Heavy-duty diesel engines
• A3/B4: High-performance, high HTHS (>3.5)
• C2/C3: Mid/low SAPS, suitable for modern Euro 6 vehicles with after-treatment systems
• C5/C6: Low-viscosity oils with enhanced fuel economy and LSPI resistance

Summary: When selecting engine oil, always verify that it meets the required API, ILSAC, or ACEA specifications. Compliance ensures performance, protection, and compatibility with emission regulations.