One thing that should be kept in mind when choosing your oil (but it isn't) is whether or not the car has a turbocharger. Many JDMs do have a turbo to increase efficiency. If you look at the manuals for these cars (I can provide links to prove my point), the manuals recommend separate grades for the turbo version and the non-turbo (that is, naturally aspirated) version. In particular, I have seen many times that while both 0w20 and 5w30 are recommended for non-turbo, only 5w-30 is recommended for the turbo version, presumably because of the very high turbo temperatures. Not always the case however. Point is be careful - if the manual says that do not use 0w20 for turbo version, DO NOT use it.
Also, the change intervals in these turbocharged cars are different. It is EXPLICITLY written in the manuals that while the oil change interval for the non-turbo version is 10k km (or one year), the change interval for turbo version is 5k km, or six months, whatever comes first. However, it is also stated that these are with 'normal' conditions. Usually, in Pakistani cities, with the hot weather, we actually fall in the severe category generally. It is then clearly stated in the manuals that in severe conditions, the change interval must be reduced further. No particular kms are given, but I would say 3500 km is safe enough.
Another thing is that is that turbos can be spoiled by something called LSPI. I don't want to get into the details (anyone can read up on Google), but the point is that LSPI can be catastrophic for turbos (a bad turbo will lead to a host of other problems soon thereafter - in fact, with a bad turbo, you can even have difficulty starting the car). Now, most engine oils DO NOT protect against LSPI. The engine oils that protect are rated SN plus or SP (these recent grades were made precisely to address LSPI). Total quartz 9000 is SN, so it doesn't protect as well against LSPI. Examples of oils in the market that protect against LSPI are Valvoline synpower 5w30 and havoline pro ds 5w30 (you can buy these from their official stores on daraz). Liquimoly molygen new generation is another (but very expensive). Just make sure the bottle says SN plus or SP.
I hope this is useful. I am a scientist/engineer, so it pains to see people following ridiculous suggestions , rather than the science. Moreover, I have maintained imported JDMs for many years now. Not a single problem. People who complain about JDMs generally don't do proper maintenance to begin with.
