Brother,
API (American Petroleum Institute) have many many standards for different types of oils. For Engine Oils, Gear Oils, Brake Oils, etc. etc. And presently from Mobil1 to PSO, all companies preparing oils according to API given standards. So there is nothing to enchant about.
Now, you've 2007 coure driven 80K, if the engine is genuine (not opened or over haul yet) then I suggest you give a sensible try to choose the oil for your car by yourself.
Firstly, forget the engine oils of PSO, Caltex, havoline, shell, Toyota, Suzuki, etc. all these are crap.
Firstly use
ZIC (5/30 or 10/30)
And carefully note the car's Pick-up, either Engine is being heated more than routine, or its giving extra noise, or reducing oil or lowering/increasing your average mileage etc.
Change it after 4K
Then use
ZIC (10/40) or Better if you use "PERFORMA's 5/40.
And then carefully observe all the things again.
Change it after 4K
Then use Performa's 20/50 or Zic HIFLOW 20/50
And then carefully observe all the things again.
Change it after 3.2K
I strongly suggest to go through these experience by yourself and learn by yourself.
Within few months, you will able to decide by yourself that what is the most suitable oil for your car.