Going up in oil grade. Is200

[Pahino.IS200]

Hello guys as you might remember i bought in is200 with 370k on the clock and its burning a bit of oil dont know if is coming from the valves or cylinder walls but since i dont have the tools for a full engine rebuild i was thinking on going on a higher grade oil like a 10w40 or even 15w40 right now I'm running 5w30 which is pretty thing for such a high mileage engine whats your opinion?

i see a bit of bluesmoke when i floor it only but I'm guessing that could be the reason why my cats failed but thats another story, outside of that no weird noises or anything only a bit of that bluesmoke when floor it? What do you think? I'll do a full rebuild on the future when this pandemic gets better since ill do the job my self.

[steve2006]

I read about this some time ago and an oil manufacturer said the same for higher mileage engines but did suggest 10W-40 only.