All engine oil is designed to maintain your vehicle’s engine health and improve its performance, but different categories of oil offer differing benefits. Here are the four most common types of oil:

• Synthetic oil - 100% of synthetic oil’s base composition is created using stronger synthesised additives for better performance at high operating temperatures.
• Part-synthetic oil - also known as Semi-synthetic or synthetic-blend, uses a base oil composition of conventional and synthetic base oils.
• High-mileage oil - offers extra protection for older engines with over 100,000 miles on the odometer.
• Mineral oil - A lubricant made from crude oil that uses no man-made chemicals.

Popular oil types are categorised by their viscosity or thickness and their resistance to flow. Visit our viscosity grades article to learn more.

• 5W-30 - The most popular engine oil for modern cars because the oil can handle a wide range of temperatures. 
• 0W-20 - Designed to flow immediately even in colder temperatures and behave as a lightweight oil once the engine is at its ideal temperature.
• 10W-40 - Extremely adaptable at performing in both winter temperatures and hotter environments. 

There are key differences between motorbike and car oil that you need to know before selecting the right one. Lubrication is the first important point because motorbike engines are smaller, so motorbike oil is designed to travel smoothly through the narrower parts of the engine. Unlike in cars, vans, and other vehicles where separate transmission fluid is used, motorbike oil also cools and lubricates the clutch and gearbox, and is designed to handle more tasks than other automotive oil. If you were to use non-motorcycle oil in your machine, you risk slipping, acceleration loss and potentially gear failure. That’s because passenger car oil contains friction modifiers that are not found in motorcycle oil.  

Castrol offers premium motorcycle oils for two and four-stroke engines and is recommended by trusted manufacturers, including Piaggio, Vespa, Moto Guzzi and Aprilia.

• 2-stroke oil - protects your engine against seizing up, reduces harmful deposits and controls exhaust smoke.
• 4-stroke oil - designed to meet the extreme demands of four-stroke motorcycle engines that typically perform at much higher levels.

While mineral oils are a cheaper alternative to synthetic options, the additives present in synthetic oils offer improved protection and performance for your engine. Choosing a fully synthetic oil can also increase your vehicle’s fuel economy and the period between oil changes compared to mineral and semi-synthetic oils. 

Oil maintenance checks are typically set by your vehicle’s manufacturer, but we would suggest checking your oil level at least every two weeks. One rule you should always follow is to run the check with our helpful guide before any long journeys to avoid breakdowns or engine damage. Regular checks combined with the right oil for your engine will result in improved protection and increased mileage for your vehicle. 

Checking your engine’s oil level is an easy part of vehicle maintenance. This process is important because running your vehicle with low oil increases stress on the engine and ould result in damages and breakdowns. Follow our simple guide on how to check your engine oil and if you need a replacement oil.

Now that you've checked your oil, you may have discovered it is time to refill your oil level. Our step-by-step guide on how to top up your engine oil can take you through the process but the main point to consider is the type of oil to use. Use our finder in the link above to find your vehicle’s optimum grade and viscosity.

Instead of waiting for your annual M.O.T., there are a few maintenance tips you can perform yourself to ensure your vehicle keeps running at its optimum level. 

• React to warning lights – most vehicle issues are easily solved and, if ignored, can develop into bigger and more expensive problems.
• Check your oil level regularly - engines perform best when oil levels are maintained, and checking only takes around five minutes.
• Avoid driving your vehicle with low fuel – Over time, deposits can form at the bottom of your fuel tank and enter the engine when levels are low. Keeping your tank at least a quarter full at all times can prevent this.
• Check your exhaust smoke – if you notice a change in the colour and thickness of your car’s exhaust smoke, it could be a sign of gasket failure.
• Keep your car clean – Getting rid of dead leaves and mud, particularly during winter, can help prevent any blockages that could affect the way your car or motorbike runs.

You should change your engine oil roughly every 5000-7500 miles, but factors such as vehicle type, age, and model should be considered, so always consult your manufacturer’s manual first. Choosing a fully synthetic oil is proven to increase the time between changes due to the beneficial additives used in the formula. Leading manufacturers Ford, Renault, Volvo, Honda, and others recommend fully synthetic oil. 

Used car oil is an environmental hazard and must be disposed of correctly. Transfer your old car oil into a container and take it to your local council’s recycling centre. As a company, we are working on ways to make sure all of our engine oil is recycled and re-refined.

Engine oil specifications or grades, are a combination of numbers and letters found on all oil packaging. They signify oil thickness (or viscosity) at high and low temperatures. 

 

For instance, for 5W-30 oil, the  “5W” part of the grade is related to the measurement of viscosity at low temperatures (-35°C) or at engine start-up. The ‘W’ tells you this because it stands for ‘Winter’. The number 30 after, signifies viscosity at 100°C, which is the normal operating temperature of most vehicle engines. Simply put, the numbers and letters tell you the oil’s viscosity when your car is stationary and in use. 

• What kind of oil does my vehicle need? – This will depend on the vehicle’s age, driving conditions and environment. Use the Castrol Oil Finder using your vehicle’s details to see which viscosity is right for your engine. 
• How many different types of oil are there? – There are four main types Synthetic Oil, Semi-Synthetic Oil, High-Mileage Oil and Mineral Oil.
• What is the difference between Synthetic Oil and Semi-Synthetic Oil?
  • FULLY SYNTHETIC: These oils still have a mineral base but are formulated with performance-enhancing additives. The additives make the oil more chemically stable and less likely to acidify or oxidise, preventing rust and corrosion from damaging your engine. Alongside performance, fully synthetic oil has a longer lifespan than semi-synthetic, offering longer periods between oil changes. 
  • SEMI-SYNTHETIC: 5W-30 semi-synthetic oils are cheaper than fully-synthetic variants because they contain fewer additives. Semi-synthetic oils still work to improve engine maintenance and performance, but more and more manufacturers today recommend fully synthetic oils for the added benefits their formula contains.