The piston ring and the cylinder wall of the old car, the gap between the crankshaft journal and the connecting Rod Bush is larger than the normal state, and the oil with higher viscosity needs better sealing function and prevent the pressure of the circuit.
The lubricating oil viscosity is closely related to the friction power of the engine, the wear of the moving parts, the sealing degree of the piston ring, the consumption of lubricating oil and fuel, and the cold start-up of the engine. Recommendations: The car wear larger vehicle, the summer national market recommended SAE 50 viscosity products; winter, the north of the Great Wall using SAE 10w-40, the Great Wall South, the Yangtze River North using SAE 15w-40, the Yangtze River south using SAE 20w-50. But the lubricant sticking through the assembly brings the following adverse effects:
▲ Low temperature start-up of the engine is difficult.
▲ the wear of parts during start-up is intensified.
▲ High power loss.
▲ cleaning effect is poor.
▲ The cooling effect is poor.