So why didnt toyota re establish oil spec for literally its largest sales market of north america?
Btw indus motors have no responsibilty to customer as they offer a joke of a warranty. This is why they "factory fill" whatever they get cheap whether its 20w50, 5w50 or 5w30 (somehow environment has changed according to you)
The older diesel corollas were filled with monograde sae40 oil, those brand new cars literally refused to start in winters in areas like quetta while parked at the showroom, they were refilled with the correct 15w40 oil which resumed normal operation.
I drive a german vehicle also, it just completed its 100,000 kms recently. Its german market and us market oil specifications are exactly the same.
Wonder why?
Same thing when you buy a japan scrap 2az fe toyota engine, it comes with the same 5w30 oil cap as I see here, likewise when i see mazda mzr 2.3 it also has the same 5w20 stickers n cap.
How come your market is so special that they had to redesign proven engines, last I checked pakistan market cars are not installing additional cooling systems, which makes your point quite comical.
The only reason im replying is because you said you have educational background in this, but all ive read till now is ancient 1920s or 1940s monograde type oil myths.
Your point is valid in vane type hydraulic pumps where additional heaters are used to flow the oil.
This is why I asked earlier abt your line of work. That maybe the rules of thumb are getting confused.
