Should I Use 30 or 40 Weight Oil for Oil Burning?
2 Answers
If your car is experiencing oil burning, it is recommended to use oil with a higher viscosity. If your car originally requires 30-weight oil, you can switch to 40-weight oil. If your car originally requires 20-weight oil, you can switch to 30-weight oil. Oil burning is generally caused by excessive clearance between the piston rings and cylinder walls, and it is common in cars with high mileage. Here is some additional information about oil: Oil burning is usually caused by excessive clearance between the piston rings and cylinder walls, and it often occurs in cars with high mileage. In some cases, oil burning in car engines is caused by a faulty oil separator. If the oil is not changed for a long time, oil burning may occur in the engine. Prolonged failure to change the oil can reduce the sealing performance of certain rubber seals inside the engine, leading to increased oil consumption.
My previous old car also had quite severe oil burning issues, and I tried different viscosity grades to figure out the pattern. 30-weight oil has better fluidity but becomes thinner at high temperatures, making it easier to seep into the combustion chamber and burn faster; 40-weight oil has slightly higher viscosity, forming a thicker oil film in the engine gaps, which can delay oil burning. I later consistently used 5W-40 full synthetic oil, paired with the habit of checking the dipstick every 5,000 kilometers. Although fuel consumption might increase by about 0.5 liters, at least I don’t need to keep an oil bottle in the trunk anymore. Actually, it also depends on the car’s age—my old car had run 180,000 kilometers before it got like this, and new cars can use 30-weight oil without any issues.
