What are the differences between engine oil 530 and 540?
2 Answers
Engine oil 530 and 540 differ in their kinematic viscosity at 100 degrees. The 540 is thicker than the 530, with a thicker oil film, matching different engine viscosity requirements. If the vehicle maintenance manual specifies the use of 530 oil, do not use 540 oil, as it will increase the resistance during engine operation, leading to reduced power and increased fuel consumption. Functions of engine oil: 1. Lubrication: There is rapid relative sliding between the piston and cylinder, and between the main shaft and bearing bush. To prevent excessive wear of parts, an oil film needs to be established between the two sliding surfaces. 2. Auxiliary cooling: Engine oil has a lower specific heat value and, being inside the engine, does not inherently have a cooling effect. However, due to the heat generated by fuel combustion in the engine, the oil can carry heat back to the oil tank and then dissipate it into the air, helping the radiator cool the engine. 3. Anti-wear: Adding a lubricant to the friction surface can reduce the friction coefficient, thereby decreasing friction resistance, saving energy consumption, and reducing wear.
The main difference between 5W-30 and 5W-40 oils lies in the numbers after the 'W'. As an ordinary office worker who commutes by car daily, I've found that 5W-30 oil makes the engine start much faster, especially in cold weather, as it flows more smoothly and reduces wear. However, 5W-40 performs better when driving on highways in summer, as its thicker consistency provides better protection against engine overheating, though it slightly increases fuel consumption. The basic difference is that the '5' before the 'W' is the same in cold temperatures, while the numbers '30' and '40' after indicate viscosity at high temperatures—30 is thinner and more fuel-efficient, while 40 is thicker and offers stronger protection. I should remind you that if you often drive short distances or in light traffic, 5W-30 is more suitable and economical. For long trips or heavy loads, 5W-40 offers more peace of mind. Always refer to your vehicle's manual when choosing to avoid mistakes.
