Engine oil is much more than just a lubricant for the engine's moving parts; it also plays a key role in cooling it. The stability of the engine at high temperatures directly depends on the condition of the oil, making it a critical element for the longevity of the car.
Modern all-season oils are designed for year-round use in most cases, as long as the manufacturer's recommendations for viscosity and change intervals are followed. However, important factors here are the climate and the technical condition of the car. For example, in the summer, it may be more appropriate to use a thicker oil. If the manufacturer allows both 0W-20 and 5W-30, then 5W-30 is preferable in hot weather, especially if winter temperatures do not fall below -30°C.
High temperatures significantly increase the load on the engine oil. It ages faster, and the thickening additives that maintain its viscosity lose their effectiveness. This can manifest as excessive fluidity of the oil even when the engine is not warmed up. Overheating, even for a short time, accelerates chemical processes in the oil, drastically reducing its protective properties. Already at 115°C, the viscosity begins to drop, which leads to increased friction and accelerated wear of critical components such as the piston group, crankshaft and timing belt.
Synthetic oils offer higher resistance to overheating. They oxidize more slowly, maintain a more stable viscosity even under extreme conditions and provide better engine protection in the long term. This characteristic makes them a preferred choice for vehicles that often operate under high loads or in hot climates.
In addition to all of the above, hot weather also increases the risk of leaks due to wear of rubber seals. Regular oil level checks and timely vehicle maintenance are key to avoiding such problems and ensuring a long and trouble-free engine life.