If you choose the wrong oil viscosity, the car may be damaged and increase fuel consumption. This is because the higher the viscosity of the oil, the greater the resistance of the internal parts of the engine, and the car needs to spray more fuel to achieve enough power, so the fuel consumption will increase. The reason why Japanese and Korean cars are fuel-efficient is that most of them use engine oil with a viscosity of 0W20.
Small viscosity oil will save fuel, but it does not mean that the car should blindly choose small viscosity oil, the vehicle has given a suitable oil viscosity model during production, which has a lot to do with the gap between mechanical parts during engine production. Blindly choosing a small viscosity oil may reduce fuel consumption in a short period of time, but there is a certain risk of easily changing the viscosity of the oil, such as engine cylinders. This is because the oil of small viscosity engine oil is relatively thin, and it is not as good as high viscosity engine oil in terms of tightness, and the oil is easy to enter the combustion chamber to participate in combustion, which not only causes an increase in oil consumption and burns engine oil in vehicles, but also aggravates carbon deposition and increases fuel consumption.
It is also not recommended to use high-viscosity oil for vehicles that have been using low-viscosity oil for maintenance, because if the oil viscosity is used too high, the fluidity of the oil will not be good, and the heat dissipation effect will become poor, which may cause overheating and wear of the engine. Because the engine is designed, the output of the oil channel and the oil pump is small, once the oil viscosity is too large, the oil supply may be insufficient, resulting in poor lubricating oil effect and increased engine cylinder pulling coefficients.
Therefore, it is best to accurately match the viscosity of the engine oil.