Picture this: you’re at the garage, about to get an oil change. The mechanic asks you what grade of engine oil you’d like, and suddenly, you’re teleported back to high school, trying to choose between Science, Commerce, and Humanities. The choices can seem overwhelming. In this blog post, we’ll look at the different engine oil grades and their related vocabulary to help you make an informed decision.
As the name suggests, engine oil is an essential component of a vehicle’s engine, performing key functions to ensure smooth and efficient operation. Think of engine oil as the vital fluid of your car – it keeps the engine clean, cool, lubricated, and efficient.
Engine oil grade refers to the level of quality and performance of engine oil based on industry standards and specifications. These standards determine the viscosity, or thickness, of the oil and its ability to flow at different temperatures, as well as the level of supplements added to provide protection, cleanliness, and durability to the engine. In simple terms, the different grades are a way to measure the ability of engine oil to perform the crucial functions of lubricating, cooling, and cleaning the engine.
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Reading an engine oil grade is easier than you think! Most engine oils are marked with a two-part identification and classification system consisting of two numbers separated by a hyphen. The first number is the oil’s viscosity rating at lower temperatures, usually expressed in the SAE (Society of Automotive Engineers) scale, and the second indicates the oil’s viscosity at higher temperatures.
For example, an engine oil marked “15W-40” would have a viscosity rating of 15 at low temperatures and 40 at high temperatures, making it suitable for use in a wider range of temperatures. A “0W” rating means that the oil is specifically formulated for use in cold weather, while a higher second number, such as “50”, indicates that the oil is thicker and better suited for high-performance engines.
But there’s more to the story. It’s important to note that not all engine oils follow the SAE identification and classification system, and some may also have additional designations, such as “synthetic” or “energy conserving”, to indicate the type of base oil and additives used. So, when choosing an engine oil, always consult your mechanic or the vehicle’s owner manual to find the recommended grade and specifications, and make sure to read the label carefully to ensure you’re getting the right oil for your car. Remember, the wrong engine oil is just as harmful as no engine oil!
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When it comes to engine oil, the different grades determine your vehicle’s smooth and efficient functioning. Here’s a closer look at a few of the commonly used engine oil grades around the world:
This type of engine oil is thin when the engine is first started. The “0W” refers to the viscosity of the oil when the engine is cold, which is 0. When the engine reaches normal operating temperature, the viscosity of the oil becomes 20
This engine oil is designed to perform like a 0-weight oil at start-up and a 30-weight oil when the engine reaches normal operating temperature
This engine oil is engineered to function as a 0-weight oil when the engine is cold and a 40-weight oil when the engine reaches normal operating temperature
This is the most commonly available and widely used engine oil in India, and many Indian car manufacturers recommend it
This is a fully synthetic engine oil that behaves like a 5-weight oil during cold start and a 40-weight oil at normal engine operating temperature
This engine oil provides a 10-weight performance at cold start and a 40-weight performance when the engine reaches normal operating temperature
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The right engine oil depends on the type of engine and driving conditions. Engine oil grades can be divided into several categories based on viscosity, performance level, and the type of base oil and additives used. Some of the most common types are:
These are the most basic and widely used engine oils, made from crude oil that has been refined and blended with additives for improved performance. They are labelled with an SAE viscosity rating such as “10W-30” or “20W-50”
Synthetic oils are human-made oils created from a concoction of different chemical compounds and offer improved performance compared to conventional oils. They provide better protection and efficiency at higher temperatures and often have a wider operating temperature range. Synthetic oils are usually labelled with the letters “SYNTH” or “SYN”, followed by their viscosity rating
High-mileage oils are designed for engines with higher mileage and provide extra protection and cleaning to older engines. They are typically labelled with “High Mileage” or “HM” on the label
These oils are designed to improve fuel efficiency and reduce emissions. They are often labelled with the “Energy Conserving” or “EC” designation and have a lower friction coefficient compared to conventional oils. These oils are less harmful to the environment and are a good step towards a sustainable future
Diesel engines require oils with higher viscosity and different additives to handle the high compression ratios and increased soot levels found in diesel engines. They are usually labelled with “CJ-4” or “CI-4+” to indicate their suitability for diesel engines
Engine oil labels contain different numbers, symbols, and abbreviations, and can often be confusing. But it’s not difficult once you familiarise yourself with the different terminologies. Here are some of the most common terms you need to know about:
SAE rating indicates the oil’s viscosity at different temperatures. For example, a label that reads “10W-40” means the oil has a viscosity of 10 at low temperatures (W stands for winter) and 40 at high temperatures
API classification indicates the oil’s performance level and suitability for use in petrol and diesel engines. The API symbol features a rain cloud design with SM or CF in the centre that identifies the oil’s performance level
ILSAC is a joint effort between the API and the Japanese Automobile Standards Organization (JASO) to develop standardised performance and fuel efficiency criteria for engine oils. The ILSAC rating is indicated by the words “ILSAC GF-x” on the label, where “x” represents the performance level
OEM indicates that the vehicle manufacturer has approved the oil for use in their engines. For example, a label that reads “Mercedes-Benz Approved” means that the oil has been tested and approved for use in Mercedes-Benz engines
API index indicates that the oil is designed to improve fuel efficiency and reduce emissions
This indicates that the oil is made from synthetic or human-made base stocks. Synthetic oils offer improved performance and protection compared to conventional oils. The word “Synthetic” or “Syn” is usually displayed on the label
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It is important to note that while engine oil grade charts can be a helpful reference, it is always best to consult your trusted mechanic or the owner’s manual of your vehicle and the oil label for the recommended specifications and approvals.
Regular oil changes are recommended based on the manufacturer’s specifications and your driving habits, typically every 12000 to 15000 kilometres or 6 to 12 months.
It’s recommended that you consult your trusted mechanic or the vehicle’s owner’s manual for the recommended oil viscosity and performance specifications. Check for API service classification, ILSAC rating, and OEM approvals.
The “20W-40″ labelling refers to the oil’s viscosity, or thickness, at different temperatures where”W” stands for winter and “20” indicates the oil’s viscosity at low temperatures, while “40” indicates its viscosity at high temperatures.