An engine oil grades list shows the different oil viscosity ratings that indicate how oil flows at various temperatures. Common grades include 0W-20, 5W-30, 10W-30, 10W-40, 15W-40, and 20W-50, where the first number (with “W”) represents cold-temperature performance and the second number indicates thickness at operating temperature. Lower-viscosity oils improve cold starts and fuel efficiency, while higher-viscosity oils offer better protection in hot conditions or high-mileage engines. Always choose the engine oil grade recommended by the vehicle manufacturer for optimal performance.

What Are Engine Oil Grades?

Engine oil grades tell you how thick or thin the oil is. This thickness is called viscosity. Different engines need different oil thicknesses. Using the right grade keeps your engine safe and working well.

What Does The Number On Engine Oil Mean?

Engine oil grades have numbers like 5W-30 or 10W-40. These numbers show the oil’s thickness in cold and hot temperatures.

• First number + W (like 5W) means how oil flows in cold weather.
• Second number (like 30) means how thick oil stays at engine heat.

Lower numbers flow easier in cold weather. Higher numbers mean thicker oil at high temperatures.

Grade	Cold Weather Performance	Hot Weather Performance	Common Use
0W-20	Very thin, good for very cold climates	Thin enough for modern engines	New cars, fuel-efficient engines
5W-30	Flows well in cold starts	Stable at normal engine temperature	Most gasoline engines
10W-40	Thicker in cold weather	Thicker at high temperature	Older engines, high mileage cars
15W-50	Thick in cold start	Very thick at high temperature	High performance and racing engines

Why Engine Oil Grades Matter

Choosing the right oil grade keeps your engine parts moving smoothly. The wrong oil can cause wear and damage.

Thinner oils protect engines in cold weather by flowing quickly. Thicker oils protect engines at high temperatures by staying in place.

Therefore different engine oil colors have different meaning which must be acknowledge to drovers.

Types Of Engine Oil Grades

Engine oil grades help define how well the oil performs under different temperatures. Types of engine oil grades mainly fall into two categories: single-grade and multi-grade oils. Each type serves specific needs based on weather and engine requirements. Understanding these types helps in choosing the right oil for your vehicle.

Single-grade Oils

Single-grade oils have a fixed viscosity. The number before the “W” (winter) or alone shows how thick the oil is at a certain temperature. For example, SAE 30 means the oil stays at the same thickness at operating temperature.

These oils are best for stable weather conditions. They work well in engines designed for specific climates, such as hot or cold regions. The main advantage is their simple formula, which makes them less costly.

Key features of single-grade oils:

• Viscosity stays constant at specific temperatures
• Usually used in older engines or simple machinery
• Less effective in varying temperatures
• Lower price compared to multi-grade oils

Here is a table showing common single-grade oil viscosities and their typical use:

Oil Grade	Viscosity at 100°C (cSt)	Typical Use
SAE 20	5.6 – 7.1	Cold climates, light engines
SAE 30	9.3 – 12.5	Warm climates, older cars
SAE 40	12.5 – 16.3	Hot climates, heavy-duty engines

Multi-grade Oils

Multi-grade oils combine two viscosity grades in one product. The label shows two numbers, like 10W-40. The first number with “W” tells how the oil flows in cold weather. The second number shows its thickness at high temperature.

These oils are designed to work well in a wide range of temperatures. They protect the engine during cold starts and keep a good oil film when the engine is hot. This makes them popular for modern vehicles.

Advantages of multi-grade oils:

1. Good performance in both cold and hot conditions
2. Reduce engine wear during start-up
3. Improve fuel efficiency
4. Suitable for most modern engines

Common examples of multi-grade oils:

• 5W-30: Good for cold starts and high temperatures
• 10W-40: Better for warmer climates
• 0W-20: Used in newer, fuel-efficient cars

Multi-grade oils contain additives that help maintain viscosity. This makes them flexible for different driving conditions and seasons. They often cost more but offer better engine protection overall.

Viscosity Ratings Explained

Viscosity ratings are key to understanding engine oil grades. They show how thick or thin oil is at different temperatures. Viscosity affects how well oil flows inside an engine. It helps protect engine parts by reducing friction and wear. Choosing the right viscosity keeps your engine running smoothly. The ratings follow a system set by the Society of Automotive Engineers (SAE). This system makes it easier to pick the correct oil for your vehicle. Below, we explain the main parts of viscosity ratings.

Research using classification algorithms revealed that compositional oil differences influence viscosity categorization — relevant in manufacturing and counterfeit detection. Journal of Analytical Chemistry.

Sae Viscosity Scale

The SAE viscosity scale measures oil thickness or flow resistance. It uses numbers like 5W, 10W, 30, or 40. The “W” stands for winter, meaning cold temperature performance. Oils with a “W” number flow better in low temperatures. Oils without “W” are rated for high temperatures. The lower the number, the thinner the oil.

• Lower SAE numbers mean thinner oil, which flows easier.
• Higher SAE numbers mean thicker oil, which protects better at high heat.
• Multi-grade oils combine two ratings, like 5W-30, working well in cold and hot.

SAE Rating	Temperature Use	Oil Thickness
5W	Cold Start	Thin, flows easily in winter
10W	Cold Start	Slightly thicker but still good for cold
30	Hot Engine	Thicker, protects at high temperatures
40	Hot Engine	Thickest, best for very hot conditions

Using the correct SAE grade helps engines start easily in cold weather. It also keeps parts safe when the engine gets hot. Check your car manual for the recommended SAE oil grade.

Cold And Hot Temperature Ratings

Engine oil must work well in cold and hot temperatures. Cold oil needs to flow quickly to protect engine parts at startup. Hot oil must stay thick enough to keep a strong oil film between moving parts.

Cold and hot ratings are part of the oil’s viscosity grade:

1. Cold Temperature Rating: Shown by the number before the “W” (winter). Lower numbers mean better flow in cold weather.
2. Hot Temperature Rating: The second number shows oil thickness at engine operating temperature. Higher numbers mean thicker oil that protects in heat.

Rating	Temperature Range	Effect on Engine
5W	-30°C to 0°C (-22°F to 32°F)	Flows easily, protects engine at cold start
10W	-25°C to 0°C (-13°F to 32°F)	Good cold protection, slightly thicker
30	Up to 100°C (212°F)	Maintains protection at normal engine heat
40	Up to 120°C (248°F)	Better for high heat or heavy loads

Choosing oil with the right cold and hot ratings prevents engine damage. Too thick oil in cold weather slows starts. Too thin oil in hot weather causes wear. Follow vehicle guidelines to match oil to your climate and engine needs.

Common Engine Oil Grades List

Common engine oil grades define the thickness and flow of oil at different temperatures. These grades help engines run smoothly by protecting parts from wear and tear. Choosing the right oil grade is vital for engine health and fuel efficiency. The Society of Automotive Engineers (SAE) sets these standards, and each grade has unique features for various driving conditions.

Sae 5w-30

SAE 5W-30 is one of the most popular engine oil grades worldwide. The “5W” means it flows well at cold temperatures, helping engines start quickly in winter. The “30” indicates its thickness at high temperatures, offering good protection during hot engine conditions.

• Excellent for cold climates and moderate to warm temperatures
• Improves fuel economy by reducing engine friction
• Commonly used in newer cars and light trucks
• Helps keep engine clean by preventing sludge buildup

Here is a quick summary of SAE 5W-30 oil properties:

Property	Description
Cold Start Viscosity	Flows easily at temperatures as low as -30°C (-22°F)
Operating Temperature	Maintains stability up to 100°C (212°F)
Applications	Passenger cars, light trucks, fuel-efficient engines

This oil is a great choice for drivers wanting reliable performance in various weather conditions.

Sae 10w-40

SAE 10W-40 oil is thicker than 5W-30, making it suitable for older engines or those in warmer climates. The “10W” rating means it performs well in cold weather but is not as fluid as 5W oils. The “40” shows it maintains good thickness at high temperatures.

• Good for vehicles with higher mileage or older engines
• Offers better protection against wear at high temperatures
• Common in moderate and hot climates
• Helps reduce oil consumption in worn engines

Benefits of SAE 10W-40 oil include:

1. Improved engine protection during hot weather
2. Enhanced lubrication for engines with slight wear
3. Better performance in stop-and-go traffic

Overall, SAE 10W-40 balances cold start ability with strong high-temperature protection.

Sae 15w-40

SAE 15W-40 is a heavier oil grade that works well in warm to hot climates. The “15W” rating means it is less fluid than 5W or 10W oils in cold weather. The “40” shows good high-temperature thickness, making it ideal for diesel engines and trucks.

• Commonly used in commercial trucks and heavy-duty vehicles
• Provides strong protection under heavy loads and high heat
• Suitable for engines operating in hot environments
• Helps reduce engine wear during long trips or towing

Key features of SAE 15W-40 oil:

Characteristic	Details
Cold Temperature Flow	Flows well above -20°C (-4°F)
Hot Temperature Viscosity	Remains thick and protective at 100°C (212°F)
Engine Types	Diesel engines, heavy-duty gasoline engines

This grade suits drivers who need durable oil for tough engine conditions.

Sae 20w-50

SAE 20W-50 is a very thick oil grade. The “20W” means it is less fluid at cold temperatures, so it is best for warm or hot climates. The “50” indicates very high viscosity at engine operating temperature.

• Ideal for high-performance or older engines with larger clearances
• Provides excellent protection at high temperatures and heavy loads
• Not recommended for cold climates due to slow flow when cold
• Common in motorcycles, classic cars, and some diesel engines

Advantages of SAE 20W-50 oil include:

1. Thicker oil film for better wear protection
2. Prevents oil breakdown in high-heat conditions
3. Helps reduce oil leaks in older engines

This oil grade suits drivers needing strong, heat-resistant lubrication.

Complete SAE J300 Engine Oil Grades Table (2025)

The SAE J300 standard, maintained by the Society of Automotive Engineers, defines the complete viscosity classification system for engine lubricants. This comprehensive table represents the latest specifications including newly introduced ultra-low viscosity grades designed for maximum fuel efficiency in modern and hybrid vehicles.

Winter Grades (Cold Performance)

Winter grades, denoted by the “W” designation, define an oil’s low-temperature performance characteristics. These ratings ensure your engine can start reliably in cold weather and that oil flows quickly to critical components during cold starts. Remember: 75% of engine wear occurs during cold starts, making winter grade selection crucial for engine longevity.

0W Specifications

• CCS Viscosity: Maximum 6,200 mPa·s at -35°C (-31°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -40°C (-40°F)
• Minimum KV100: 3.8 mm²/s
• Best For: Extreme cold climates, Arctic conditions, fastest cold-start protection
• Temperature Range: Effective down to -40°C
• Key Benefits: Instant oil flow in brutal cold, reduced battery strain, immediate engine protection

The 0W grade represents the pinnacle of cold-weather performance, engineered for regions where temperatures regularly plunge below -30°C. This grade is mandatory for vehicles operated in northern Canada, Alaska, Scandinavia, and other extreme cold environments.

5W Specifications

• CCS Viscosity: Maximum 6,600 mPa·s at -30°C (-22°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -35°C (-31°F)
• Minimum KV100: 3.8 mm²/s
• Best For: Cold to moderate climates, most versatile winter grade
• Temperature Range: Effective down to -35°C
• Key Benefits: Excellent all-season performance, widely available, proven reliability

The 5W grade is the most popular winter grade globally, offering outstanding cold-start protection for the vast majority of climates. It provides the ideal balance between cold-weather performance and year-round protection.

10W Specifications

• CCS Viscosity: Maximum 7,000 mPa·s at -25°C (-13°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -30°C (-22°F)
• Minimum KV100: 4.1 mm²/s
• Best For: Moderate climates, warmer regions with mild winters
• Temperature Range: Effective down to -30°C
• Key Benefits: Good cold performance, lower viscosity modifier content, cleaner operation

While less common in modern passenger vehicles, 10W grades remain popular in commercial applications and regions with milder winters. The slightly higher viscosity at cold temperatures can benefit older engines.

15W Specifications

• CCS Viscosity: Maximum 7,000 mPa·s at -20°C (-4°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -25°C (-13°F)
• Minimum KV100: 5.6 mm²/s
• Best For: Warm climates, heavy-duty diesel engines, high-mileage vehicles
• Temperature Range: Effective down to -25°C
• Key Benefits: Excellent for hot climates, traditional diesel choice, robust film strength

The 15W grade is the workhorse of the heavy-duty diesel world, particularly in the iconic 15W-40 configuration used in millions of commercial trucks and agricultural equipment worldwide.

20W Specifications

• CCS Viscosity: Maximum 9,500 mPa·s at -15°C (5°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -20°C (-4°F)
• Minimum KV100: 5.6 mm²/s
• Best For: Hot climates only, older engines, specific applications
• Temperature Range: Effective down to -20°C
• Key Benefits: High-temperature protection, minimal viscosity modifiers

The 20W grade is suitable only for consistently warm climates where temperatures rarely drop below freezing. It’s primarily found in 20W-50 formulations for high-performance and vintage applications.

25W Specifications

• CCS Viscosity: Maximum 13,000 mPa·s at -10°C (14°F)
• MRV Viscosity: Maximum 60,000 mPa·s at -15°C (5°F)
• Minimum KV100: 9.3 mm²/s
• Best For: Desert environments, tropical regions, racing applications
• Temperature Range: Not suitable below -15°C
• Key Benefits: Maximum hot-weather protection, near single-grade characteristics

The 25W grade is extremely rare in consumer applications and primarily used in specialized racing, military, or industrial equipment operating in consistently hot environments.

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Summer Grades (Operating Temperature)

Summer grades define an oil’s viscosity at normal operating temperature (100°C/212°F) and under high-temperature, high-shear conditions (150°C/302°F). These ratings ensure adequate protection when your engine reaches full operating temperature and is under load.

SAE 8

• Kinematic Viscosity at 100°C: 4.0 to 6.1 mm²/s
• HTHS Viscosity at 150°C: Minimum 1.7 mPa·s
• Introduction Date: January 2015 (SAE J300 revision)
• Primary Purpose: Maximum fuel economy in hybrid and ultra-efficient engines
• Typical Applications: Select hybrid vehicles (Honda, Toyota, Mazda)
• Common Combinations: 0W-8

Real-World Performance: Laboratory testing demonstrates that properly formulated 0W-8 oils provide equivalent wear protection to conventional 5W-30 oils despite being significantly thinner. This is achieved through cutting-edge additive chemistry, particularly enhanced ZDDP (zinc dialkyldithiophosphate) levels and molybdenum-based friction modifiers.

SAE 12

• Kinematic Viscosity at 100°C: 5.0 to 7.1 mm²/s
• HTHS Viscosity at 150°C: Minimum 2.0 mPa·s
• Introduction Date: January 2015
• Primary Purpose: Fuel economy optimization for small displacement engines
• Typical Applications: Fuel-efficient compact cars, select European models
• Common Combinations: 0W-12

Market Position: SAE 12 fills the gap between the ultra-thin SAE 8 and the more established SAE 16 grade. It was introduced at Honda’s request after successful testing showed improved fuel economy without compromising engine durability in their Fit and similar models.

SAE 16

• Kinematic Viscosity at 100°C: 6.1 to 8.2 mm²/s
• HTHS Viscosity at 150°C: Minimum 2.3 mPa·s
• Introduction Date: Pre-2015 (earlier adoption)
• Primary Purpose: Balance of fuel economy and protection
• Typical Applications: Modern Japanese vehicles, select domestic models
• Common Combinations: 0W-16, 5W-16

Adoption Leader: The SAE 16 grade gained widespread acceptance following its specification in millions of Honda, Toyota, and Lexus vehicles from 2018 onward. It’s now one of the fastest-growing viscosity grades in North America.

SAE 20

• Kinematic Viscosity at 100°C: 6.9 to 9.3 mm²/s
• HTHS Viscosity at 150°C: Minimum 2.6 mPa·s
• Historical Significance: Traditional “light” oil grade
• Primary Purpose: Fuel economy with proven protection
• Typical Applications: Mainstream passenger vehicles since 2000s
• Common Combinations: 0W-20, 5W-20, 10W-20

Widespread Use: SAE 20 grade oils (particularly 5W-20 and 0W-20) became the default specification for millions of Ford, Honda, Toyota, and General Motors vehicles throughout the 2000s and 2010s. They represent the “sweet spot” for most modern engines.

SAE 30

• Kinematic Viscosity at 100°C: 9.3 to 12.5 mm²/s
• HTHS Viscosity at 150°C: Minimum 2.9 mPa·s
• Historical Significance: Classic automotive standard
• Primary Purpose: Traditional all-around protection
• Typical Applications: Universal—most versatile grade
• Common Combinations: 0W-30, 5W-30, 10W-30

Industry Workhorse: The SAE 30 grade represents over a century of refinement and remains the most specified viscosity grade worldwide. The 5W-30 formulation alone accounts for approximately 40% of global passenger car motor oil volume.

SAE 40

• Kinematic Viscosity at 100°C: 12.5 to 16.3 mm²/s
• HTHS Viscosity at 150°C: Minimum 3.5 mPa·s (3.7 for 15W-40, 20W-40, 25W-40)
• Historical Significance: Traditional heavy-duty standard
• Primary Purpose: High-load, high-temperature protection
• Typical Applications: Diesel engines, older vehicles, hot climates
• Common Combinations: 5W-40, 10W-40, 15W-40, 20W-40, straight SAE 40

Heavy-Duty Champion: SAE 40 remains the global standard for commercial diesel engines, with 15W-40 being specified in the majority of Class 8 trucks, buses, and agricultural equipment. The higher HTHS requirement (3.7 vs 3.5 mPa·s) for certain winter grades ensures adequate protection under severe conditions.

SAE 50

• Kinematic Viscosity at 100°C: 16.3 to 21.9 mm²/s
• HTHS Viscosity at 150°C: Minimum 3.7 mPa·s
• Primary Purpose: Extreme duty protection, racing, vintage vehicles
• Typical Applications: High-performance engines, worn engines, hot climates
• Common Combinations: 15W-50, 20W-50, straight SAE 50

Performance Application: SAE 50 grades are the choice for air-cooled engines (motorcycles, VW Beetles), race engines running high temperatures, and older engines with increased bearing clearances. The thick oil film provides maximum protection under extreme stress.

SAE 60

• Kinematic Viscosity at 100°C: 21.9 to 26.1 mm²/s
• HTHS Viscosity at 150°C: Minimum 3.7 mPa·s
• Primary Purpose: Maximum film strength for extreme applications
• Typical Applications: Racing engines, vintage/classic cars, industrial equipment
• Common Combinations: 20W-60, straight SAE 60

Specialized Use: SAE 60 represents the heaviest passenger car motor oil grade. It’s specified for early BMW M-series engines (10W-60), extreme racing applications, and certain air-cooled aircraft engines. Modern engines with tight tolerances should never use SAE 60 unless specifically required.

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Multi-Grade Oil Combinations: Full List

Multi-grade oils combine a winter grade and operating temperature grade to provide protection across a wide temperature range. This is achieved through viscosity index improvers (VII)—polymeric additives that expand when heated, maintaining viscosity at high temperatures while remaining fluid when cold.

Ultra-Low Viscosity Grades

These revolutionary grades represent the cutting edge of lubrication technology, designed specifically for maximum fuel efficiency in hybrid vehicles and ultra-efficient internal combustion engines meeting stringent CAFE (Corporate Average Fuel Economy) standards.

0W-8 (Newest Grade for 2026+ Vehicles)

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS), 60,000 mPa·s max at -40°C (MRV)
• Hot: 4.0-6.1 mm²/s at 100°C, 1.7 mPa·s min at 150°C (HTHS)

Specifications:

• JASO GLV-1 (Gasoline Low Viscosity)
• Not yet covered by ILSAC GF-6 or GF-7 standards
• Requires specialized testing per JASO M366 for fuel economy

Current Applications (2025-2026):

• 2023+ Toyota Corolla (2.0L M20A-FKS engine)
• 2023+ Toyota Yaris/Yaris Cross Hybrid
• 2024+ Mazda2 Hybrid (1.5L VVT-i)
• Select Honda Fit hybrid models (Japan/Asia markets)

Fuel Economy Benefits:

• 2-3% improvement over 0W-16 in hybrid applications
• Up to 5% improvement over conventional 5W-30
• Critical for manufacturers meeting 2026+ CAFE targets requiring 8% yearly efficiency gains

Availability: Limited but growing rapidly. Major brands now offering 0W-8:

• Liqui Moly Special Tec AA 0W-8
• Motul Hybrid 0W-8
• Wolf Ecotech 0W-8 GLV-1
• HPL Premium Plus 0W-8

Expert Recommendation: Never use 0W-8 unless explicitly specified in your owner’s manual. Modern engines designed for this grade have tighter tolerances and oil system pressures calibrated specifically for ultra-low viscosity operation.

0W-12

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS)
• Hot: 5.0-7.1 mm²/s at 100°C, 2.0 mPa·s min at 150°C (HTHS)

Specifications:

• API SP (approved 2022)
• Can be licensed under existing GF-6 framework
• Uses standard API/ILSAC test sequences

Current Applications:

• Limited OEM specifications as of 2025
• Primarily used in specific hybrid configurations
• Expected broader adoption in 2026-2028 model years

Performance Testing: Independent testing by Oak Ridge National Laboratory demonstrated that properly formulated 0W-12 oils can outperform conventional 5W-30 synthetics in wear protection while delivering superior fuel economy. Wear metals in used oil analysis showed lower iron, copper, and lead levels after 10,000-mile intervals.

0W-16

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS)
• Hot: 6.1-8.2 mm²/s at 100°C, 2.3 mPa·s min at 150°C (HTHS)

Specifications:

• ILSAC GF-6B (specific standard, not backwards compatible)
• API Shield symbol (not Starburst)
• API SP certification

Widespread Applications:

• 2018+ Honda Accord (1.5L turbocharged)
• 2016+ Lexus ES300h, RX450h
• 2018+ Toyota Camry (2.5L hybrid)
• 2020+ Subaru Outback (2.5L)
• 2019+ Acura RDX

Important Distinction: GF-6B oils (0W-16) carry the Shield symbol rather than the Starburst, indicating they are NOT backwards compatible with older vehicles requiring GF-6A oils. This prevents consumers from accidentally using 0W-16 in engines designed for thicker oils.

Fuel Economy Impact: Real-world testing shows 0W-16 provides 1-2% fuel economy improvement over 5W-20 and 2-3% over 5W-30 in most driving conditions. Over 100,000 miles, this can represent hundreds of dollars in fuel savings.

0W-20

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS)
• Hot: 6.9-9.3 mm²/s at 100°C, 2.6 mPa·s min at 150°C (HTHS)

Specifications:

• ILSAC GF-6A, GF-7A
• API SP, API SQ (2025)
• Most widely available ultra-low viscosity grade

Dominant Market Position: 0W-20 became the dominant specification for Japanese automakers throughout the 2010s and remains extremely popular:

• Honda (majority of 2010-2020 models)
• Toyota (Camry, RAV4, Highlander 2010-2020)
• Mazda (most 2010+ models)
• Subaru (most 2011+ models)

Versatility: Available from virtually every oil brand in conventional, synthetic blend, and full synthetic formulations. Price competitive with 5W-30, making it an easy transition for consumers.

Climate Suitability: Excellent for all climates, from -40°C Arctic conditions to +45°C desert heat. The 0W cold rating ensures reliable starting in extreme cold, while the SAE 20 operating viscosity provides adequate protection in hot weather.

0W-30

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS)
• Hot: 9.3-12.5 mm²/s at 100°C, 2.9 mPa·s min at 150°C (HTHS)

Specifications:

• ILSAC GF-6A, GF-7A
• API SP, API SQ
• ACEA C2, C3 (European versions)

Primary Applications:

• European vehicles (BMW, Mercedes-Benz, Volkswagen)
• Premium Japanese vehicles
• High-performance variants requiring cold-weather protection

European Popularity: 0W-30 is the most common specification for modern European vehicles, particularly those with diesel particulate filters (DPF) or gasoline particulate filters (GPF). ACEA C2 and C3 specifications require mid-SAPS (Sulfated Ash, Phosphorus, Sulfur) formulations to protect exhaust after-treatment systems.

Performance Characteristics: 0W-30 offers an excellent balance between cold-start protection and high-temperature film strength. It’s particularly favored for turbocharged engines operating under high boost pressures.

0W-40

Viscosity Profile:

• Cold: 6,200 mPa·s max at -35°C (CCS)
• Hot: 12.5-16.3 mm²/s at 100°C, 3.5 mPa·s min at 150°C (HTHS)

Specifications:

• ACEA A3/B4, C3
• Various OEM approvals (BMW LL-01, MB 229.5)
• API SP

Primary Applications:

• High-performance European vehicles
• Cold-climate performance cars
• Turbocharged performance engines

Performance Orientation: 0W-40 represents the intersection of maximum cold-weather starting and robust high-temperature protection. It’s the go-to choice for enthusiasts living in northern climates who demand both winter reliability and track-day protection.

Popular Choices:

• Mobil 1 0W-40 (European Car Formula)
• Castrol Edge 0W-40
• Liqui Moly Leichtlauf High Tech 0W-40

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Popular Mainstream Grades

These grades represent the most commonly specified oils for passenger vehicles worldwide, balancing protection, fuel economy, and affordability.

5W-20

Viscosity Profile:

• Cold: 6,600 mPa·s max at -30°C (CCS)
• Hot: 6.9-9.3 mm²/s at 100°C, 2.6 mPa·s min at 150°C (HTHS)

Market Dominance: For nearly two decades (2000-2020), 5W-20 was THE specification for:

• Ford (F-150, Mustang, Explorer—virtually all gasoline models)
• Chrysler/Dodge/Jeep (most 2005+ models)
• Many General Motors vehicles

Volume Production: At its peak (2015), 5W-20 represented approximately 30% of all motor oil sold in North America—hundreds of millions of quarts annually.

Transition Period: As of 2025, many automakers have shifted newer models to 0W-20, but millions of vehicles on the road still require 5W-20, ensuring robust demand for years to come.

5W-30 (Most Common Grade Globally)

Viscosity Profile:

• Cold: 6,600 mPa·s max at -30°C (CCS)
• Hot: 9.3-12.5 mm²/s at 100°C, 2.9 mPa·s min at 150°C (HTHS)

Universal Champion: 5W-30 is THE most widely specified motor oil viscosity grade in history:

• Over 40% of global passenger car oil volume
• Specified by more vehicle manufacturers than any other grade
• Available from every oil brand in multiple quality tiers

Why It Dominates:

• Perfect balance of cold-start protection and operating temperature viscosity
• Suitable for -30°C to +45°C temperature range
• Works in gasoline and diesel engines
• Proven reliability over 50+ years of continuous use

Applications:

• Majority of GM vehicles (especially pre-2015)
• Nissan, Infiniti (most models)
• Kia, Hyundai (pre-2020)
• Commercial vehicles
• Small engines (alternative to straight 30-weight)

Quality Tiers:

• Conventional: Basic API SN/SP protection
• Synthetic Blend: Improved temperature stability
• Full Synthetic: Maximum protection, extended drain intervals
• High Mileage: Enhanced seal conditioners for 75,000+ mile engines

Expert Opinion: If you’re ever uncertain about oil choice and your vehicle was built before 2015, 5W-30 is almost certainly a safe, effective choice. It’s the “default” grade for good reason.

5W-40

Viscosity Profile:

• Cold: 6,600 mPa·s max at -30°C (CCS)
• Hot: 12.5-16.3 mm²/s at 100°C, 3.5 mPa·s min at 150°C (HTHS)

European Heritage: 5W-40 is the traditional specification for European vehicles, particularly:

• Volkswagen/Audi (VW 502.00/505.00)
• BMW (except LL-01 which calls for 0W-40)
• Mercedes-Benz (MB 229.3, 229.5)
• Porsche

Performance Applications: Popular in:

• Turbocharged engines
• High-performance vehicles
• Vehicles experiencing severe duty cycles
• Towing/hauling applications

Diesel Dominance: 5W-40 is nearly universal in European diesel passenger cars, providing the robust film strength needed for high-pressure common-rail fuel systems and DPF-equipped vehicles.

10W-30

Viscosity Profile:

• Cold: 7,000 mPa·s max at -25°C (CCS)
• Hot: 9.3-12.5 mm²/s at 100°C, 2.9 mPa·s min at 150°C (HTHS)

Traditional Favorite: 10W-30 was THE recommended grade for:

• 1980s-1990s American vehicles
• Small engines (lawn mowers, generators)
• Moderate climate regions

Current Status: While less common in new vehicles, 10W-30 remains popular for:

• Older vehicles (pre-2000)
• Small engine equipment
• Commercial/industrial applications
• Budget-conscious consumers (often less expensive than 5W-30)

Advantages:

• Lower viscosity modifier content than 5W-30 (potentially cleaner operation)
• Excellent hot-weather protection
• Good for high-mileage engines in warm climates

10W-40

Viscosity Profile:

• Cold: 7,000 mPa·s max at -25°C (CCS)
• Hot: 12.5-16.3 mm²/s at 100°C, 3.5 mPa·s min at 150°C (HTHS)

Motorcycle Standard: 10W-40 is THE specification for most motorcycles:

• Sport bikes
• Touring motorcycles
• Adventure bikes
• Many ATVs and UTVs

Historical Automotive Use: Common in 1970s-1990s vehicles, particularly:

• High-mileage engines
• Hot climate applications
• Performance vehicles of the era

Current Applications:

• Motorcycles (dominant grade)
• Older vehicles (1990s and earlier)
• High-mileage vehicles in warm climates
• Some diesel passenger cars (Europe)

Important Note: Modern passenger car engines (2000+) generally should NOT use 10W-40 unless specifically called for. The thicker viscosity can reduce fuel economy and, in some cases, may not provide adequate flow to variable valve timing components.

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High-Viscosity Grades

These thicker oils provide maximum film strength for specialized applications, older engines, and extreme operating conditions.

15W-40

Viscosity Profile:

• Cold: 7,000 mPa·s max at -20°C (CCS)
• Hot: 12.5-16.3 mm²/s at 100°C, 3.7 mPa·s min at 150°C (HTHS)

Heavy-Duty Diesel King: 15W-40 is THE specification for:

• Class 8 heavy-duty trucks (Freightliner, Peterbilt, Kenworth)
• Agricultural equipment (tractors, combines, harvesters)
• Construction equipment (excavators, bulldozers, loaders)
• Marine diesel engines
• Commercial diesel generators

Global Dominance: Estimated 60-70% of all heavy-duty diesel engines worldwide run 15W-40. It’s the default specification for engines meeting API CK-4 and FA-4 standards.

Why It Dominates Diesel:

• Robust HTHS viscosity (3.7 mPa·s) protects high-pressure fuel systems
• Excellent soot handling capability
• High TBN (Total Base Number) for acid neutralization
• Proven durability for extended drain intervals (25,000-50,000 miles)

Quality Tiers:

• API CK-4: Current heavy-duty diesel standard
• API CJ-4: Previous generation (still widely used)
• API CI-4 PLUS: Older but adequate for many applications

Automotive Applications: Some older diesel pickup trucks (pre-2011) specified 15W-40, though most modern diesels now use 5W-40 or lower viscosity grades.

20W-50

Viscosity Profile:

• Cold: 9,500 mPa·s max at -15°C (CCS)
• Hot: 16.3-21.9 mm²/s at 100°C, 3.7 mPa·s min at 150°C (HTHS)

Classic Muscle Car Oil: 20W-50 is synonymous with:

• 1960s-1970s American muscle cars
• Air-cooled VW engines (Beetle, Bus)
• Classic British sports cars (MG, Triumph)
• High-performance motorcycles (especially cruisers)

Hot Climate Specialist: Ideal for:

• Southern U.S. (Arizona, Texas, Florida)
• Middle East
• Australia
• Any region where temperatures rarely drop below 0°C

High-Mileage Applications: Popular for engines with:

• 150,000+ miles
• Increased bearing clearances
• Minor oil consumption issues
• Older seals that may leak with thinner oils

Popular Brands:

• Castrol GTX 20W-50 (legendary status among classic car enthusiasts)
• Valvoline VR1 20W-50 (high zinc for flat-tappet cams)
• Shell Rotella T 20W-50 (diesel-rated for heavy duty)

Racing Heritage: 20W-50 remains popular in vintage racing and classic car competition, where maximum film strength under high RPM and high temperature is critical.

20W-60

Viscosity Profile:

• Cold: 9,500 mPa·s max at -15°C (CCS)
• Hot: 21.9-26.1 mm²/s at 100°C, 3.7 mPa·s min at 150°C (HTHS)

Specialized Applications:

• Early BMW M3/M5 (S14, S38 engines specified 10W-60)
• Race engines with significant bearing clearances
• Heavily modified performance engines
• Certain air-cooled aircraft engines
• Industrial equipment in extreme heat

Extreme Protection: With a kinematic viscosity up to 26.1 mm²/s at 100°C, 20W-60 provides the thickest oil film available in passenger car motor oil. This extreme thickness is necessary only in very specific circumstances:

• Race engines with .004″+ bearing clearances
• Engines experiencing oil temps above 130°C regularly
• Air-cooled engines with uneven temperature distribution

Modern Relevance: Very limited. Most modern engines would experience significant power loss and reduced fuel economy with 20W-60. Use only if explicitly specified or when working with vintage/race engines under professional guidance.

Warning: Never use 20W-60 in a modern engine (2000+) with variable valve timing, turbochargers, or tight tolerances. The excessive viscosity can starve oil-actuated components and potentially cause engine damage.

Api Service Classifications

API Service Classifications help identify the right engine oil for different types of engines. The American Petroleum Institute (API) sets these standards to ensure oils meet specific performance levels. These classifications are split mainly into two groups: one for gasoline engines and another for diesel engines. Choosing oil with the correct API rating protects your engine, improves fuel efficiency, and extends engine life.

Gasoline Engine Oils

Gasoline engine oils have API service categories that start with the letter S. The letter S stands for “Service” or “Spark Ignition,” which refers to gasoline engines. Each new letter after S indicates a newer, improved oil standard. For example, API SN is newer and better than API SM.

Common API gasoline oil classifications include:

• SA – Used for very old engines, no longer suitable for modern cars.
• SB – Slightly improved but still outdated.
• SC to SJ – Oils for older cars, now mostly replaced.
• SL, SM, SN, SP – Modern oils for most gasoline engines.

The latest API service classification for gasoline engines is SP. It protects against deposits, wear, and helps improve fuel economy.

API Classification	Key Features	Suitable For
SL	Protects against sludge and wear	Cars from 2001 and older
SM	Improved oxidation resistance	Cars from 2004 and older
SN	Better deposit control and fuel economy	Most modern gasoline cars
SP	Protects turbochargers, reduces engine wear	Latest gasoline engines

Use the API classification recommended in your vehicle manual. Using a lower-rated oil can harm the engine. Higher-rated oils offer better protection and performance.

Diesel Engine Oils

Diesel engine oils have API service categories starting with the letter C. The letter C stands for “Commercial” or “Compression Ignition.” Diesel engines need oils that can handle higher pressures and soot levels.

API diesel oil classifications include:

• CA, CB, CC – Early diesel oil standards, now outdated.
• CD – For older, high-speed diesel engines.
• CE, CF, CF-2, CG-4, CH-4 – Oils for newer diesel engines with better pollution control.
• CI-4, CJ-4, CK-4, FA-4 – Latest oils for modern diesel engines with emission systems.

Modern diesel oils protect engines from wear, control soot, and support emission systems.

API Classification	Main Benefits	Use For
CH-4	Good soot handling and wear protection	Diesel engines 1998-2002
CI-4	Better oxidation and deposit control	2002-2010 diesel engines
CJ-4	Protects emission systems, reduces wear	Modern diesel engines from 2007
CK-4 / FA-4	Latest high performance, fuel economy	New diesel engines with emission controls

Always use diesel oil with the API rating your engine needs. Using incorrect oil risks damage and poor engine life. Diesel oils also help keep engines clean and running smoothly under tough conditions.

Choosing The Right Grade

Choosing the right engine oil grade is important for your vehicle’s performance and engine life. Engine oil grades tell you how thick or thin the oil is at different temperatures. Picking the correct grade helps your engine run smoothly, saves fuel, and protects parts from wear. Many factors affect this choice, including what the vehicle manufacturer suggests, the weather where you live, and the age of your car. Understanding these points will help you select the best oil grade for your engine.

Manufacturer Recommendations

Vehicle makers test engines with specific oil grades. They list the best grades in the owner’s manual. This information is key to choosing oil that fits your engine’s needs. Using the recommended grade keeps the warranty valid and avoids engine problems.

Look for these details in the manual:

• Viscosity grade: Usually shown as numbers like 5W-30 or 10W-40.
• Oil type: Synthetic, semi-synthetic, or conventional.
• Performance standards: API or ACEA ratings that show quality.

Here is a simple table showing a few common grades and their typical uses:

Oil Grade	Weather Suitability	Common Use
5W-30	Cold and warm climates	Modern gasoline engines
10W-40	Warmer climates	Older gasoline and diesel engines
0W-20	Very cold climates	Fuel-efficient, new engines

Never choose an oil grade lower or higher than the manufacturer’s advice. The wrong grade can cause poor lubrication or engine damage.

Climate Considerations

Climate affects how oil behaves in your engine. Oil must flow easily when cold and protect parts when hot. Choosing a grade that fits your region’s temperature is key.

Use this guide for temperature ranges:

• Cold climates: Use oils with lower “W” numbers like 0W or 5W. These oils flow well in freezing temperatures.
• Hot climates: Oils with higher second numbers like 30 or 40 work better. They stay thick and protect in heat.
• Mixed climates: Multi-grade oils like 5W-30 or 10W-40 adapt to changing weather.

Below is a temperature guide for common oil grades:

Oil Grade	Cold Start Temp (°F)	Max Operating Temp (°F)
0W-20	-35	212
5W-30	-22	212
10W-40	-13	230

An experimental analysis of commercial 5W-30 oils showed up to 25% variance in viscosity within the same SAE grade, underlining that real-world oil behavior can differ significantly from nominal ratings.

Vehicle Age And Condition

Older vehicles or those with high mileage often need different oil grades than new cars. Engine wear and seals can affect how oil works inside the engine.

Consider these points:

1. Older engines: Usually benefit from thicker oils like 10W-40 to reduce leaks and improve lubrication.
2. High mileage engines: Special high-mileage oils contain additives that protect worn parts and reduce oil burn.
3. New engines: Use thinner oils like 0W-20 or 5W-30 for better fuel economy and faster oil flow.

Here is a simple chart for oil grade by vehicle age:

Vehicle Age	Recommended Oil Grade	Reason
0-5 years	0W-20 or 5W-30	Fuel efficiency, fast flow
5-10 years	5W-30 or 10W-30	Balanced protection and flow
10+ years	10W-40 or high-mileage oil	Thicker oil for worn engines

What Type of Engine Oil Do I Need?

Synthetic Vs Conventional Oils

Choosing the right engine oil is important for your vehicle’s health. Two common types are synthetic oils and conventional oils. Both serve the same basic purpose: to lubricate engine parts and reduce wear. Yet, they differ in how they are made and how they perform. Understanding these differences helps pick the best oil for your engine.

Advantages Of Synthetic Oils

Synthetic oils are man-made from refined chemical compounds. This process creates oil that performs better in many ways than conventional oil. Here are the key benefits:

• Better engine protection: Synthetic oils resist breakdown at high temperatures.
• Improved cold starts: They flow faster in cold weather, reducing engine wear.
• Longer oil change intervals: Synthetic oils last longer before needing replacement.
• Cleaner engine: They contain fewer impurities, helping reduce sludge build-up.
• Better fuel efficiency: Synthetic oils reduce engine friction, which can save fuel.

Here is a quick comparison table of synthetic and conventional oil features:

Feature	Synthetic Oil	Conventional Oil
Temperature Performance	Excellent at high and low temps	Good at moderate temps
Oil Change Interval	7,500 to 15,000 miles	3,000 to 5,000 miles
Engine Cleanliness	Less sludge, fewer deposits	More impurities, sludge risk
Cost	Higher price	Lower price

Using synthetic oil helps your engine run smoother and last longer. It is ideal for newer cars and extreme driving conditions.

When To Use Conventional Oils

Conventional oils are made from crude oil with some refining. They work well for many engines, especially older models or cars with simple needs.

Here are situations when conventional oil fits best:

1. Older vehicles: Engines designed before synthetic oils became common often run fine on conventional oil.
2. Shorter drives: Cars mostly used for short trips and low speeds don’t need synthetic oils.
3. Lower cost priority: Conventional oils cost less and suit drivers on a budget.
4. Regular oil changes: If you change oil frequently, conventional oil is a practical choice.
5. Standard driving conditions: Normal city or highway driving without extreme heat or cold.

Here is a summary table to help decide when conventional oil works well:

Condition	Recommended Oil Type
Older engine (10+ years)	Conventional
Short trips & low speeds	Conventional
Budget-friendly option	Conventional
Frequent oil changes	Conventional
Normal temperature range	Conventional

Conventional oils provide basic protection and meet most engine requirements. They remain a good choice for many drivers and vehicles.

Frequently Asked Questions

What Are The Common Engine Oil Grades Available?

Common engine oil grades include 5W-30, 10W-40, and 15W-50. These numbers indicate viscosity and temperature performance. Choosing the right grade ensures proper engine lubrication and protection under various conditions.

How Do Oil Grades Affect Engine Performance?

Oil grades impact engine efficiency by controlling flow and protection. Lower numbers flow better in cold, higher numbers protect at high heat. Using the correct grade maintains engine health and fuel economy.

Why Is Multi-grade Oil Important For Engines?

Multi-grade oils, like 10W-30, perform well in cold and hot temperatures. They prevent engine wear during startup and maintain viscosity during operation. This versatility improves engine longevity and performance.

Can Using Wrong Oil Grade Damage My Engine?

Yes, using the wrong oil grade can cause poor lubrication, increased wear, and overheating. It may reduce engine lifespan and efficiency. Always follow manufacturer recommendations for optimal engine protection.

Conclusion

Choosing the right engine oil grade helps your vehicle run smoothly. Each grade fits different engines and weather conditions. Check your car manual for the recommended oil type. Using the correct grade protects your engine and saves money. Regular oil changes keep your engine clean and healthy.

Remember, good oil means better engine life and performance. Keep this list handy for future reference. Your engine will thank you. Simple steps make a big difference.