Can 15w40 engine oil be used in sedans?

[McGianna]

15w40 engine oil can be used in sedans. The grade of engine oil is established to distinguish different operating conditions in various environments. As long as the viscosity performance and various indicators of the engine oil meet the standards set by the original vehicle, it can be used. Introduction to engine oil: 1. 15w40 engine oil is a multi-grade oil, where 15W represents the minimum operating temperature of the oil, which is -25°C for 15W oil; while 40 represents the maximum operating temperature of the oil. The higher the number, the greater the viscosity and the higher the applicable maximum temperature. 2. Excessive oil viscosity can increase engine operating resistance and wear.

[DelTravis]

Can 15W40 engine oil be used in a sedan? My opinion is, it depends on your car model and usage environment. My old car has been using 15W40 for over a decade, and it provides good protection in high temperatures, such as preventing engine overheating during highway driving in summer. However, I wouldn't recommend it for modern sedans. In winter, 15W40 is too thick, making cold starts difficult, increasing fuel consumption, and potentially causing faster engine wear. Checking your vehicle's manual is the most reliable approach—some older cars or vehicles in tropical regions may be suited for it. Regular oil changes are more important; don't save small money only to spend big on repairs. Overall, unless specified in the manual or in hot environments, don't risk using high-viscosity oil.

[EdenAnn]

15W40 engine oil can be used in passenger cars, but with caution. I've seen many car owners use it to save money, only to experience slow starts in winter, a 20% surge in fuel consumption, and increased engine noise. Modern passenger cars are designed for low-viscosity oils like 5W30 or 0W20, which have better flow properties and protect the engine. 15W40 is suitable for older vehicles or diesel engines, but in urban driving conditions, it can lead to carbon buildup and acceleration difficulties. I recommend checking your vehicle's manual to confirm the recommended specifications—don't rely on neighbors' experiences. Choosing the wrong oil can result in higher long-term repair costs. It's safest to consult a professional during maintenance.

[DeArthur]

I've tried 15W40 oil in my sedan. It worked fine in summer with sufficient lubrication and no significant change in fuel consumption. But come winter, the engine took forever to start and acceleration felt sluggish. The manual specifies 5W30 – modern engines are precision-built, and lower viscosity oil suits daily commuting better. If you're in tropical regions or drive an older car, it might work, but monitor engine condition regularly. After switching to lower viscosity, the car runs much smoother with better fuel efficiency and eco-friendliness. Don't neglect oil level checks – regular maintenance matters more than oil grade.