Well I guess you should keep using 5w-50 as per your routine without watching this thread again.
Same Toyota, same engine, same people, for same environment (PK) were recommending 5w-30 & 10w-30 SL grades.
Toyota PK introduced their own oils, I guess in 2010 only with 20w-50 SL grade. And soon after they introduced 10w-30 SM.
Both blended by MAL Pakistan, but clearly these oils did not catch people’s interest despite cheap in price.
When liquid Moly & Mobil, introduced their oil 5w-50 (I guess in 2011) and it was very very expensive oil. But people start using it assuming that its best oil for PK atmosphere.
Toyota immediately pick up the point and launched their own 5w-50 which was “Half in price” as compared to LM & Mobil. And finally they win people’s attraction for it.
Remember, earlier they were filling 5w-30 SL grade in same Toyotas with same engines.
So its clearly about making money.
My Fav. Quotation.
Making money is not difficult, but THINKING how to make money makes the difference.