The right oil depends on your vehicle's engine type, manufacturer specifications, and driving conditions. Check your owner's handbook for the recommended viscosity grade and specification (such as ACEA C3 or API SN). You can also use our oil finder tool above — it asks a few quick questions to help narrow down suitable options from our range.

Fully synthetic oil is manufactured entirely from chemical compounds, offering superior protection at extreme temperatures, better fuel economy, and longer service intervals. Semi-synthetic oil blends synthetic and mineral base stocks, providing improved performance over mineral oil at a lower cost than full synthetic. Most modern vehicles benefit from fully synthetic oil, while semi-synthetic is suitable for older engines and less demanding driving conditions.

The numbers in an oil grade indicate its viscosity (thickness) at different temperatures. The number before the W (which stands for Winter) shows how the oil flows in cold conditions — lower means thinner and easier flow during cold starts. The number after the W indicates viscosity at operating temperature. So 5W-30 flows well in cold weather while maintaining adequate thickness to protect your engine at normal running temperature.

Oil change intervals vary depending on the vehicle, oil type, and driving conditions. Most modern vehicles using fully synthetic oil can safely run 10,000 to 15,000 miles or 12 months between changes, whichever comes first. Frequent short journeys, towing, or dusty conditions may require more frequent changes. Always follow the intervals recommended in your vehicle's service schedule.

Mixing oils of the same specification and viscosity grade from different manufacturers is generally safe, as industry standards ensure base compatibility. However, mixing different viscosity grades or specification levels is not recommended, as it can alter the oil's performance characteristics. If you need to top up, match the existing oil as closely as possible.

Diesel engines typically require oils meeting ACEA C-class specifications (such as C3 or C5), especially if the vehicle has a diesel particulate filter (DPF). Using the wrong oil in a DPF-equipped diesel can cause blockages and expensive damage. Check your handbook for the exact specification, or use our oil finder tool — it walks you through the key questions to narrow down suitable products.

For most modern engines, fully synthetic oil provides measurable benefits including better cold-start protection, improved fuel efficiency, and extended drain intervals that can offset the higher per-litre cost. Older engines designed for mineral oil may not see the same benefits. The best approach is to use the oil type and specification recommended by your vehicle manufacturer.

Using oil with an incorrect specification can lead to increased engine wear, reduced fuel economy, and potential damage to emission control systems like DPFs and catalytic converters. Using oil that is too thin may not protect adequately under load, while oil that is too thick can increase fuel consumption and restrict flow at cold starts. Always match the oil specification in your vehicle handbook.

While some oils are formulated specifically for petrol or diesel engines, many modern multi-grade oils carry both API and ACEA ratings that cover both fuel types. The critical factor is matching the correct specification. Diesel engines with particulate filters have stricter requirements around sulphated ash and phosphorus content, so it is important to use oil labelled as DPF-compatible for those vehicles.

Your vehicle's recommended oil specification is printed in the owner's handbook, usually in the maintenance or technical specifications section. You can also find it on the oil filler cap on some vehicles, or by contacting your dealer. Our oil finder tool can help narrow down suitable products by asking about your vehicle type, fuel, and usage.