Whatever you do, if your car is low on oil, don’t simply top it up with the first engine oil you find. Using the correct oil grade and specification is important for protecting your engine and maintaining performance.
How To Find Out Which Oil Your Car Needs
Many drivers are surprised to learn that not all engine oils are the same.
If your oil warning light comes on or you need to top up the oil level, the first place to check is your vehicle handbook. Manufacturers specify the correct oil grade and, in some cases, recommended oil standards for your engine.
You’ll typically see oil grades displayed in a format such as:
5W-30
or
5W-40
These numbers indicate the oil’s viscosity and how it performs in different temperatures.
Using the wrong oil occasionally may not cause immediate damage, but repeatedly using an incorrect specification can increase engine wear and reduce long-term reliability.
What Is Engine Oil Viscosity?
Viscosity refers to how easily an oil flows.
Engine oils must perform effectively in both cold starts and normal operating temperatures, which is why modern oils are designed to maintain suitable protection across a wide temperature range.
For example:
5W-30
- The “5W” refers to the oil’s cold-weather performance.
- The “30” refers to its viscosity when the engine is operating at normal temperature.
Choosing the correct viscosity helps ensure proper lubrication, reduces wear, and allows the engine to operate efficiently.
Your vehicle handbook will always provide the recommended viscosity grade for your engine.
What Are The Most Common Types Of Engine Oil?
Two of the most commonly used engine oils are:
- 5W-30
- 5W-40
These grades are suitable for a wide range of modern petrol and diesel vehicles.
Other grades, such as 0W-30, may be specified for certain engines where improved cold-start performance is required.
The correct oil will vary depending on factors such as:
- Manufacturer recommendations
- Engine design
- Vehicle age
- Climate conditions
- Driving habits
Always check the manufacturer’s guidance before topping up or replacing engine oil.
Why Using The Correct Oil Matters
Engine oil plays a critical role in:
- Lubricating engine components
- Reducing friction
- Preventing overheating
- Protecting against wear
- Helping maintain fuel efficiency
Regular oil checks and servicing can help prolong engine life and maintain the vehicle’s overall condition.
A well-maintained vehicle is often more attractive to buyers and may retain its value better over time.
You may also want to read our article on dashboard warning lights, which explains what common engine and oil-related warning indicators mean and when action should be taken.
For more advice on servicing, maintenance schedules, and keeping your car in excellent condition, visit our maintenance guidance hub.
Related Reading
Regular servicing goes hand in hand with correct oil maintenance, so if you’re unsure on how you can tell when you should change your oil, we’ve got all the information you need here.
Final Thoughts
Choosing the correct engine oil is one of the simplest but most important parts of vehicle maintenance.
Checking your handbook, using the correct viscosity grade, and keeping oil levels topped up can help protect your engine, improve reliability, and support long-term vehicle value.
If you’d like to find out what your vehicle is worth today, you can get an instant valuation here.