Normally the manuals recommends thin oils (except Suzuki cars) and people blindly start pouring Zic A+ 5/20, Shell X7 5/30, etc. etc.
But if I have PDM and start using Zic A+, then I cannot still use this oil till the car is over 70K driven in Pak. Or, lets consider from another way. I just buy 2nd hand PDM driven 230K and its manual says use 5/30 oil. Then still it will be wise to use that recommended oil in the car who has already driven 230K in Pak? Never !! So here comes our common sense to use and we have to choose the oil according to the engine condition, covered mileage, etc..
Manuals (in Pak. for Pak. Cars) never says to pour fully synthetic oils in the cars. Because they know very well that these oils are far superior than even the new PDMs.
And since the JDMs are in the market, the synthetic oils are getting popular. Incredible sales has been recorded for LM, Mobil1, PTT Performa, KIXX, ZIC and other companies who brought such fine quality oils. If JDMs are not here, 99% people still be using 20/50 oil in all types of cars for sure.
If PDM manual says to pour 5/30 oil (which is NOT fully synthetic oil), we can fully guarantee to feed 5/40 fully synthetic oil for better results.