Understanding Engine Oil – Viscosity and Classifications Explained
You know where the dipstick is but what does the viscosity of engine oil mean? How do you know if it is the correct oil for your vehicle? The LUBE-LINK oil and lubricant database is a great tool to start with before discussing with a qualified mechanic, it allows you to find the right oil quickly and effortlessly. All you need is the make and model of your vehicle, equipment, or machinery.
Always follow OEM recommendations for fluid viscosity and API service category. KLONDIKE takes no responsibility for product misuse or misapplication.
Types of Engine Oil
Full Synthetic Engine Oil
Full synthetic engine oil will deliver maximum protection and performance with superior low and high temperature performance even in extended high stress service conditions.
Full synthetic engine oil has gone through a chemically engineered process. Full synthetic oils use higher quality base oils, are processed to remove all impurities, and are customized with higher performing additives compared to conventional oils.
Full synthetic engine oils are the preference of OEM’s, making up the vast majority of factory fill engine oils today. Higher performing engines with higher efficiency generate more heat and full synthetic engine oils help resist heat induced oxidation and deposit buildup inside the engine.
Synthetic Blend Engine Oil
Synthetic blend engine oil uses a combination of synthetic and conventional base oils for added resistance to oxidation and wear compared to conventional engine oil.
High Mileage Engine Oil
KLONDIKE Synthetic Blend High Mileage Engine Oils are designed for use in passenger cars and light trucks that have exceeded 120,000 kms
Conventional Engine Oil
Conventional engine oils are usually the most economical option since they require less refinement and re-engineering. Conventional engine oil contains additives to help with fuel economy and protection against corrosion and wear; meeting basic OEM performance standards.
SAE Viscosity Grades
The Society of Automotive Engineers (SAE) has developed a rating system to classify oil viscosity, such as 5W-30, 10W-30 and 15W-40. Fluids that are thin have a low viscosity, and fluids that are thick have a high viscosity. Engine oil also changes in viscosity measurement as it is heated or cooled.
For an 5W-20 oil, the “5” is the cold-temperature viscosity rating (The “W” stands for winter indicating its suitability for use in cold temperatures), and the “20” is the high temperature viscosity rating. The lower the number, the lower the temperature at which the oil can be used for safe and effective engine protection. Higher numbers reflect better protection for high-heat and high-load situations.
Most engine oils are multi-viscosity, meaning they behave differently at different operating temperatures, good cold flow when the temperature drops and reliable protection once the engine reaches operating temperature.
Engine Oil Classifications
How is engine oil classified?
The American Petroleum Institute (API) developed a classification system to identify oils formulated to meet the different operating requirements of gasoline and diesel engines.
The API system has two general categories: S-series and C-series. The S-series service classification emphasizes oil properties critical to gasoline engines. The classifications progress alphabetically as the level of lubricant performance increases. Each classification replaces those before it. Oils meeting the latest API classification, API SP, may be used in any engine calling for it or a previous API specification unless otherwise specified.
How is diesel engine oil classified?
C-series classifications relate to diesel engines. Not all C-series classifications supersede one another. Note the FA-4 classification, which pertains only to some 2017 and newer diesel engines. The FA-4 classification was introduced primarily to help maximize fuel economy in over-the-road trucks.
The API/ILSAC “Starburst”
The institute’s Starburst stamp of approval signifies oils which meet the latest International Lubricant Specification Advisory Committee (ILSAC) standard. The ILSAC standards are developed by vehicle and engine manufacturers, oil and additive companies and industry trade associations such as API, ACC, ASTM, and SAE.
The API/ILSAC Starburst is found on the front label of qualified Engine oil bottles.
The API “donut”
The API “donut” is found on the back label and identifies oils that meet current API engine oil standards.
- The top of the “Donut” displays the engine oil’s API performance standard. The letter “S” followed by another letter (API SP) refers to oil suitable for gasoline engines as outline in the above chart. The letter “C” followed by another letter and number (API CK-4) refers to oil suitable for diesel engines.
- The centre of the “Donut” shows the oil’s SAE viscosity grade.
- The bottom of the “Donut” highlights whether the engine oil has certain resource or energy conserving properties
The API “Shield” signifies oils which meet the current ILSAC GF-6B engine protection standard and fuel economy requirements of the International Lubricant Specification Advisory Committee (ILSAC). This mark can only be applied to oils having a viscosity grade of 0W-16.
Select the Correct Engine Oil
Engine oil is a vital part of your engine’s longevity and performance. The initial price of a high-quality full synthetic engine oil may be more, but the lifetime cost can be far less compared to conventional oil, especially if you get your car regularly serviced. Use the LUBE-LINK search tool and ask for KLONDIKE Engine Oil when you get your next oil change.