Should I Use 30 or 40 Weight Oil for Oil Burning?
3 Answers
Whether to use 30 or 40 weight oil for oil burning depends on the following situations: 1. If the car originally uses 30 weight oil, then 40 weight oil can be used. 2. If the car originally uses 20 weight oil, then 30 weight oil can be used. The following are the reasons for oil burning: 1. Excessive clearance between the piston rings and cylinder walls, which is likely to occur in cars with high mileage. 2. Failure of the oil-gas separator. 3. Not changing the oil for a long time, resulting in reduced sealing performance of some rubber seals in the engine.
Last time I went for maintenance, I also inquired about this issue. If the car is getting old and starts burning oil, using 40 viscosity oil can indeed help, especially for older turbocharged cars like Volkswagen. However, you need to pay attention to the temperature. For example, in our northern region where it can drop to minus twenty degrees Celsius in winter, 40 viscosity oil is too thick during cold starts and can actually harm the engine. My experience is that it's safer to use 5W-40 in summer and switch to 0W-30 in winter. Also, don't just focus on changing the oil; check the dipstick every 5,000 kilometers. If the consumption exceeds half a liter, it's likely that the piston rings need repair.
After ten years in the repair shop, I've handled over a hundred cars with oil burning issues. Choosing between 30 or 40 depends on wear severity: if blue smoke from the exhaust is particularly noticeable, stick with 40 oil—its higher viscosity can fill gaps. If consumption is just fast without smoke, 30 is sufficient. A key reminder: avoid haphazard use of repair additives. Last week, I fixed an Audi where a leak stopper ended up clogging the oil pump screen. Honestly, if it's burning less than half a liter, there's no need to fuss—keeping 1L of oil in the trunk is more reliable than any quick fix.
