I know about two models in Indonesia. I know about 13 and 14 inch options. I also agree with you that different tyre sizes accept different tyre pressure. But that's not what I am trying to discuss here.
You didn't understood my point. You were saying pressure of 36 PSI is wrong. I can't believe how could you say manufacturer is wrong? By manufacturer I mean the actual engineers who worked on the car, not Pak Suzuki.
Secondly you said Wagon R came with 14inch tyres originally which was not the case in Pakistan even for CBU units. I informed you about that in my previous comment.
Regarding engine oil, I am simply following what the manual says and i.e. 0W-20. I am not a moron who follow what Pak Suzuki mechanic says.
You know what benefit I get from following 100% owners manual?
1) My car after 3 years drive better than cars that are 6 months old of persons who I know. It shifts better because I use closest possible gear oil grade that manual says.
2) My mileage is insane. I get around 25 km/l from Wagon R
Check the screen shot for proof