Answers to many car questions live in the owners manual. Naturally, the manual is a good reference for how often to replace oil and which oil type to use.
Factory guidance on viscosity should not be ignored. If the manual offers only one option, it is usually best to follow it, especially while the car is under warranty.
Manufacturers sometimes state they have not tested oils with different viscosities and cannot guarantee engine performance outside the prescribed range. For example, AVTOVAZ recommends using oils with a working viscosity of 30 at air temperatures up to 25°C, and switching to 20W-50 when temperatures exceed 45°C.
There are additional considerations for engine oil changes when accounting for seasonal variations in driving conditions.
The viscosity of the oil, which SAE standards describe with two numbers and the letter W, directly influences the engine’s operating temperature range. An example is 0W-20. The first digit indicates low-temperature properties that affect cold starting, while the second digit shows how viscosity changes at normal operating temperatures.
Engine oil needs to be changed…
1. Like long runs
Drivers who log under 10,000 miles per year may view seasonal oil changes as unnecessary. Using a wide-range oil (for example, 5W-40) and driving smoothly can work. However, if annual mileage reaches tens of thousands, it makes sense to top up with thicker oil for warmer seasons.
2. If you live in a cold region
Location matters. Residents in southern regions may get by with year-round driving on oils like 10W-40, but areas with a strong continental climate often benefit from seasonal changes. Viscosity should also align with the region’s maximum annual average temperatures.
3. When you go south
Travelers and those with heavy loads in hot, sunny climates may need seasonal oil changes. After a high-mileage period with significant warm-weather driving, extra care for the engine becomes reasonable. In such cases, very low viscosity settings can strain the engine.
4. If the motor is worn out
The term oil wear issues raises questions about the engine’s condition. If the engine is aging, spring oil changes paired with a higher viscosity oil can reduce oil consumption and help extend engine life.
It is wise to carry a liter of the same oil used in the engine. It takes little space and can be useful for topping up.
This is how car manufacturers view the need for seasonal oil changes.
Car manufacturers: change by mileage
The consensus among official representatives from Hyundai, Jaguar Land Rover, Mazda, Subaru, Renault, Volvo, Mitsubishi, and Kia is that the oil currently in a vehicle is suitable for all weather conditions. In general, oil should be changed according to mileage: Subaru recommends every 15,000 km, Volvo every 20,000 km, and others follow their own schedules.
If operating conditions are tough, switching more often is fine. However relying on the calendar and temperature alone is not mandatory.
AVTOVAZ provides a straightforward approach: consult the owner’s manual, then use the table to determine the correct oil quality level and viscosity class for the car within the existing temperature range.
If needed, change the oil according to the table, which shows the temperature ranges associated with each viscosity class: from -40 to -25°C, from -30 to -25°C, and so on.
The suitability of oils is therefore linked to the operating region and prevailing temperatures rather than seasonal changes. An oil change is typically advised every 10,000 to 15,000 kilometers or once a year, depending on the model.
In short, the decision is driven by the thermometer rather than the calendar. That feels like a practical answer.
Expert opinion — Behind the wheel
When changing engine oil, never use products with a lower quality class than what the manufacturer recommends. It is possible to adjust viscosity within the manufacturer’s guidelines, but seasonal changes should still reflect those recommendations. More frequent oil changes can benefit the engine, but they should always follow manufacturer guidance.
- The American Cyclo automotive chemicals and SUPROTEC additives help maintain the vehicle’s components and assemblies in good condition.
- Learn how to properly maintain a car through the books of the publisher Behind the Wheel.
- Driving can also be explored on Viber.