I have a mid-aged 300k 3.6L car. I bought it 3 years ago and was using 20w50 oil (I live in Saudi Arabia where tempartures reaches 50c in summer and below 10c in winter)
The 20w50 was so heavy on my engine even in summer so I refered to the owners manual, they (Chevrolet) recommended 10w30.
The 10w30 was so successful the past year. Winter and summer, the engine gained more power, less fuel consumtion and less heat.
3 months ago I suffered oil leaks due to 1-litre of oil over the required qunaitity that borke some seals in my engine and I fixed them but still suffer oil loss.
I guess it is mostly evaporation through the PCV as I don't notice suspicious smokes from the exhaust.
The question, If I move back to a thicker oil, will that help or should I fix something else?