The only oil with that viscosity in Pakistan is Kixx Neo 0W-20. Next best thing you can find is Zic A+ 5W-20.
Pak Suzuki is making customers fool by selling crap old spec oil for a modern vehicle like WagonR. I know now people will start saying that's it's not good for our weather but that's total non-sense. The owners manual contain recommendation from engine manufacturers. Now you me tell yourself that the manufacturer know better about the engine or this Pak Suzuki or people suggested honey like thick oils?
I won't try to convince you just by saying things here without proofs. I can prove two things.
First, it's always best to follow manual recommendation. I achieve about 28-30 kpl mileage on highway by just following the manual.
=> I use Zic A+ 5W-20 (I would love to use Kixx 0W-20 but Zic has this facility of free home delivery and you are 100% satisfied that it's genuine oil)
=> Zic Gear FF 75W-85 gear oil (manual says 75W-80 which is not available in Pakistan. Pak Suzuki is offer flat SAE 90 I guess. Way too thick for Wagon R)
=> 36psi tyre pressure (check door side sticker of driver's seat). Yes 36psi is the recommendation, not 30psi.
=> Clean air filter between 1000-2000km.
Second fact I would like to prove is by numbers/specs of engine oil. People usually think using 5W or 10W or 20W is good for Pakistan. That's absolute myth.
For example according to specs of Kixx Neo 0W-20 and Zic A+ 5W-20:
Kixx 0W-20 have 48.2 viscosity @ 40C temp and Zic A+ have 52.3 viscosity @ 40C temp so for cold start 0W-20 is much better than 5W-20. In other words the engine will have less wear specially when you start it in the morning even in summers.
Now if you compare the viscosity at 100C (the operating temperature of the non-turbo engine), Kixx 0W-20 have 8.8 viscosity and Zic A+ have 8.9 viscosity. Which means at operating temperature of engine i.e. 100C the viscosity of both oils will be same.
This example proves that you must better look for viscosity at 40C no matter what brand it's. So to summarize, check manual of your car. Suppose it says 5W-30. Now look for 0W-30 oil instead of 5W-30 because both of these oils will have same viscosity at operating temperature but 0W will better lubricate your engine at cold start and hence less wear will occur. Both Zic OW 0W-30 and Kixx Neo 0W-30 are good oils because they have almost same specs.
But if you drive a lot on highways like motor way or nothern areas (hill climbing), or towing, etc, then yes you definitely need thick oil maybe like 0W-30 in case of Wagon R. But for city driving or even on highways like Islamabad highway, you can safely use 0W-20 as recommended by the manual.
Now instead of listening to people who know nothing about oils and keep suggesting honey like oils to others, better go and read some books of different authors. They will suggest you the same thing which I summarized here.
Reading material:
1) Motor Oil 101 - Bob is the Oil Guy - Bob is the Oil Guy
The author of this guide uses 5W-20 even in his Ferrari only when he drives in city. But for race track, he uses bit thick oils.
2) Comprehensive book on Motor Oil
http://vwts.ru/vw_doc2/the_motor_oil_bible.pdf
