The difference between motor oil 5W-30 and 5W-40 is that the kinematic viscosity is different, the oxygen resistance is different, and the dirt removing property is different.

I, different kinematic viscosity

1, oil 5W-30: oil 5W-30 at 100 ℃ kinematic viscosity of 30, lower than the oil 5W-40 viscosity.

2, motor oil 5W-40: motor oil 5W-40 at 100 ℃ kinematic viscosity of 40, higher than the motor oil 5W-30 viscosity.

Two, different oxygen resistance

1, motor oil 5W-30: motor oil 5W-30 oxygen resistance is worse than motor oil 5W-40, in the start-up of the engine protection ability is worse.

2, motor oil 5W-40: motor oil 5W-40 is better than motor oil 5W-30 in terms of oxygen resistance, better protection of the engine at startup.

Three, the decontamination of different

1, oil 5W-30: oil 5W-30 than oil 5W-40 has a better inhibition of carbon, varnish and sludge generation or will be the effect of these deposits removed.

2. 5W-40: 5W-40 is less effective than 5W-30 in inhibiting or removing carbon, varnish and sludge.

Baidu Encyclopedia - Motor Oil

Baidu Encyclopedia - Motor Oil Marker