Should You Use 30 or 40 Weight Oil for Aggressive Driving?
2 Answers
For aggressive driving, 40 weight oil is preferable. During high-speed driving, 40 weight oil can maintain good lubrication performance, whereas 30 weight oil's protective effect diminishes as temperatures rise, leading to increased wear. The difference between 30 and 40 weight oil: The grade after the oil classification indicates its viscosity specification. "W" stands for Winter, and the smaller the number before it, the better the oil's low-temperature fluidity, meaning it can be used in lower environmental temperatures and provides better engine protection during cold starts. The number after W represents the oil's kinematic viscosity at 100°C—the higher the number, the higher the viscosity. 40 weight oil has higher viscosity than 30 weight oil and is suitable for higher maximum temperatures. Hazards of aggressive driving: During aggressive driving, the engine's air intake is substantial, fuel injection is high, combustion inside the engine cylinders is very intense, and the torque output from the crankshaft position is significant. As a result, the torque borne by various internal engine components naturally increases.
I've been driving for 20 years and often engaged in aggressive driving, like high-speed sprints or mountain road racing. In such situations, the engine can't withstand the pressure, and using the wrong engine oil can easily damage it. Personally, I prefer using 40 viscosity grade oil, such as SAE 40, because it's thicker and can better coat high-temperature components, especially during rapid acceleration or prolonged high RPMs, preventing oil film breakdown and protecting engine longevity. I remember using 30-grade oil before, and after a few aggressive drives, the engine noise increased significantly. Later inspection revealed severe wear. Now, I stick to full synthetic 40-grade oil and change it every 5,000 kilometers. In short, always refer to your vehicle's manual, don't take risks, and prioritize safety.
