I seek your advice on engine oil, would really appreciate input from @Xulfiqar and/or @capsat
Its Honda Civic 2007 having 150K plus on odo. It was owned by a doctor and has been completely maintained by Honda authorized dealership throughout.
As I understand, user manual recommended engine oil is 5w30 which is what I have bought, however the shopkeeper and an "expert" mechanic there strongly recommended not to pour thin oil in this old engine with 150K reading. They strongly advised to use at least 10w40. Although, having gone through the manual, I was fully convinced that 5w30 is the right viscosity for this car, after strong opposition from these guys, I am now confused.
I would really appreciate it if you could answer following questions:
1) Is using 5w30 going to harm the engine? (except for that it may result in quicker evaporation requiring a relatively shorter interval of top up, if at all).
2) Is this a myth or reality that older engine should always be fed thicker oil irrespective of anything else. if so, what should be threshold odometer reading to classify and engine as older? or is there any other criteria for this?
Many thanks in advance
