How to Read the Engine Oil Label

In our days there is a various number of engine oil types and of course each type is different in its own way. So if you put the wrong kind of oil in your vehicle, you can cause some damage and get an expensive bill for the repair. Before purchasing any oil for your vehicle, it is very important to know how to read the label.
With the appearance of the first wheel, people realized how destructive friction force can be. Components wore out so quickly that it was required to come up with a solution as quick as possible. Animal fat was used as the first lubricant, and it was only in the middle of the 19th century that a different solution was found. It was in 1866 when the first trademarked motor oil brand appeared, called Valvoline.
In our days there is a various number of engine oil types and of course each type is different in its own way. So if you put the wrong kind of oil in your vehicle, you can cause some damage and get an expensive bill for the repair. Before purchasing any oil for your vehicle, it is very important to know how to read the label.
Viscosity Grades
The first thing you will notice is the viscosity grade in form of 5W-30, 10W-40, 15W-40 and so forth. The viscosity grade of engine oil provides information on the oil’s resistance to flow through the engine under certain conditions. The oil with a low viscosity grade will be more liquid, more fluid and as a result will flow more easily. And vice versa, the higher the grade, the thicker the oil, slowing its flow to help form a protective film across the parts.

Because the engine oil is affected by temperature, its viscosity grade gives information on the use of it when hot and cold. So the “W” stands for Winter and together with the number preceding it, points out what the viscosity is when the weather temperature drops to freezing point and below. While the second number, after W, indicates viscosity at higher temperatures, when the engine is actually running.
As an example 5w30 engine oil has a winter viscosity grade of five, meaning it is less viscous at low temperatures, compared to 10w30. And it has a hot viscosity grade of 30, which means it is just as viscous as 10w30 at high temperatures but less viscous than oils such as 10w40.
Before deciding which oil to use it is important to consult your engine manufacturer about exactly which grade of oil is appropriate for your vehicle.
Service Classifications
Apart from the viscosity grade you can see a two-letter code, listed on the motor oil label, that tells you which types of vehicles the oil is designed for. It begins with either a letter S for gasoline engines or a letter C for diesel engines.

The second letter tells you which model years the oil is designed to work with. For the letter A, the oil meets requirements of vehicles that were developed in 1920s. The classification of current vehicles is N, so that the two-letter code should read SN for owners of relatively new, gasoline powered cars manufactured after 2011.
The service classification of engine oils is classified by the American Petroleum Institute (API). The program certifies that engine oil meets certain Original Equipment Manufacturer (OEM) quality and performance standards. The service classification is shown in the API "Service Symbol Donut" on the product label.
In Europe there are ACEA standards, based on testing developed by the European Engine Lubricants Quality Management System (EELQMS). ACEA system of classification is updated every 4 years (the latest being 2016) and are made up of a letter(s) - A/B, C, E, that highlight the class and a number that defines the categories. A/B refers to passenges car motor oils (A refers to petrol and B to diesel), C to catalyst compatible motor oils, and E to heavy duty diesel engine oils. The classes are further devided into categories. For example the category A5/B5, part of A/B class, have lower HTHS (High Temperature High Shear) viscosity than A3/B3, which means that the oil provide better fuel economy but may not provide enough protection in engines that are not designed for them.
Below you can find the ACEA categories in "Consumer Language".
A/B: Gasoline and Diesel Engine Oils – “High SAPS”
- A1/B1 Category is removed with these Oil Sequences.
- A3/B3 Stable, stay-in-grade Engine Oil intended for use in Passenger Car & Light Duty Van Gasoline & Diesel Engines with extended drain intervals where specified by the Engine Manufacturer, and for severe operating conditions as defined by the Engine Manufacturer.
- A3/B4 Stable, stay-in-grade Engine Oil intended for use at extended Drain Intervals in Passenger Car & Light Duty Van Gasoline & DI Diesel Engines, but also suitable for applications described under A3/B3.
- A5/B5 Stable, stay-in-grade Engine Oil intended for use at extended Drain Intervals in Passenger Car & Light Duty Van Gasoline & Diesel Engines designed to be capable of using Low Viscosity Oils with HTHS Viscosity of 2.9 to 3.5 mPa*s. These Oils are unsuitable for use in certain Engines - consult vehicle-OEM’s owner’s manual/handbook in case of doubt.
C: Catalyst & GPF/DPF compatible Engine Oils for Gasoline & Diesel Engines – “Low SAPS”
Note: These Oils will increase the DPF/GPF and TWC life and maintain the Vehicle’s Fuel Economy.
Warning: Some of these Categories may be unsuitable for use in certain Engine Types – consult the vehicleOEM’s owner’s manual/handbook in case of doubt.
- C1 Stable, stay-in-grade Engine Oil with Lowest SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Low Viscosity Oils with a minimum HTHS Viscosity of 2.9 mPa*s.
- C2 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Low Viscosity Oils with a minimum HTHS Viscosity of 2.9 mPa*s.
- C3 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Oils with a minimum HTHS Viscosity of 3.5 mPa*s.
- C4 Stable, stay-in-grade Engine Oil with Low SAPS-Level, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable of using Oils with a minimum HTHS Viscosity of 3.5 mPa*s.
- C5 Stable, stay-in-grade Engine Oil with Mid SAPS-Level, for further improved Fuel Economy, intended for use as catalyst compatible Oil at extended Drain Intervals in Vehicles with all Types of modern Aftertreatment Systems and High Performance Passenger Car & Light Duty Van Gasoline & DI Diesel Engines that are designed to be capable and OEM-approved for use of Low Viscosity Oils with a minimum HTHS Viscosity of 2.6 mPa*s.
E: Heavy Duty Diesel Engine Oils
- E4 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for some EGR engines and some engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers shall be consulted if in doubt.
- E6 Stable, stay-in-grade oil providing excellent control of piston cleanliness, wear, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under very severe conditions, e.g. significantly extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for EGR engines, with or without particulate filters, and for engines fitted with SCR NOx reduction systems. E6 quality is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low sulphur diesel fuel. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers shall be consulted if in doubt.
- E7 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV and Euro V emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines without particulate filters, and for most EGR engines and most engines fitted with SCR NOx reduction systems. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers shall be consulted if in doubt.
- E9 Stable, stay-in-grade oil providing effective control with respect to piston cleanliness and bore polishing. It further provides excellent wear control, soot handling and lubricant stability. It is recommended for highly rated diesel engines meeting Euro I, Euro II, Euro III, Euro IV, Euro V and Euro VI emission requirements and running under severe conditions, e.g. extended oil drain intervals according to the manufacturer’s recommendations. It is suitable for engines with or without particulate filters, and for most EGR engines and for most engines fitted with SCR NOx reduction systems. E9 is strongly recommended for engines fitted with particulate filters and is designed for use in combination with low Sulphur diesel fuel. However, recommendations may differ between engine manufacturers so driver manuals and/or dealers should be consulted if in doubt.
SAPS: Sulphated Ash, Phosphorus, Sulphur
HTHS: High Temperature High Shear Viscosity
DI: Direct Injection
DPF: Diesel Particle Filter
GPF: Gasoline Particle Filter
TWC: Three-Way Catalyst
And to represents the interest of American and Japanese manufacturers, in 1992 was created the International Lubricant Standardization and Approval Committee (ILSAC). The ILSAC standards, represented by the terminology ILSAC GF-x, are based on the API service categories and guide additional performance requirements like fuel economy improvement.
Year ---------- API -------- ILSAC
1994 - 1995 ---- SH --------- GF-1
1996 - 2000 ---- SJ ---------- GF-2
2001 - 2004 ---- SL ---------- GF-3
2005 - 2010 ---- SM --------- GF-4
2010 - present - SN --------- GF-5
API/ILSAC oils are compatible with ACEA-rated oils so you can easily mix the two oils of the same weight together and be sure that they will not degrade the performance of either product.
Type of engine oil
Inside the owner's manual of any vehicle should be a section that talks about the right type of engine oil that is required for your vehicle. And you will find these types marked on oil labels as well.
Fully Synthetic Engine Oil
Fully synthetic oil is a lubricant made of a synthetic base stock, mixed with additional additives, and passed through an extensive treatment in the lab to make it significantly superior to its mineral counterpart. Synthetic engine oil is designed to have best mechanical properties and is used in the most challenging conditions like motorsport and extreme weather condition.
Conventional / Mineral Engine Oil
Mineral engine oil is the petroleum-based oil derived from the refining of crude petroleum. It undergoes special treatment to perform across a wide temperature range and gets fortified with additional additives to comply with particular requirements.
Compared to synthetic engine oil, mineral oil flows through the engine slower and can result in increased fuel consumption. And other thing to remember, it needs to be changed more frequently than synthetic oils.
Semi-Synthetic Engine Oil
Semi-synthetic oil is a mixture of fully synthetic engine oil blended in with mineral oil to boost its properties without increasing its price by much. So it offers fewer performance enhancements and protects components less than synthetic oils but is purer, better-flowing and longer-lasting than mineral oil.
