Well, we had this debate like 2 years back when my car wasn’t delivered, and I was asking for the best oil. You advised not to go above Xw30. I chose toyota 10w30 oil and continued that for next 15000kms. Issue I faced were brief tick tick noise of vvti at coldstart and vibration at 2000rpm. Made one trip to north pakistan at6000kms and oil was making burning smell when it was only driven 2000kms.
Well, i thought of switching to 5w50 toyota taglon which is a fully synthetic according to IMC. I felt little or no issue on it, but cold start noise was still there. At every 4000kms this oil tends to reduce acceleration of car. Flushed engine at 35000kms and sent taglon for lab testing. Results were shocking, VI was just 117 which should be around 170 after 5000kms usage. Poured 5w40 liqui moly synthoil hightech fully synthetic with its ceratec and all issue were gone and there was no or pretty less noise on cold startup, acceleration was way smoother, and engine noise was minimal.
At 56k kms last month, i came to know that liqui moly fully synthetic in Pakistan is api SM and not of latest grade, and all api SN are semisynthetics.
I went for mobil 1 5w50, engine noise reduced to a much greater extent, there is no tick tick or grinding at coldstartups now and accleration is optimal yet smoother. Fuel economy is also the same 11-12km/l within city, and 15-17km/l on highways. Everybody says that 50 is highly viscous for this engine, but my engine is performing way better than any 5w30 or 5w40. I must say that one should also consider the factor of heat, humidity, dust/pollution and bad fuel quality in Pakistan.