Is this a 0W20 spec engine? It's looking like more and more people are running a W30 in W20 spec engines, me included. Makes me wonder if in fact a W30 oil is better at protecting an engine from wear than a W20.
IMO. 0W20 oils do not necessarily cause more engine wear and switching to a xW30 will not necessarily protect your engine better for a vehicle that is spec'd for 0W20. Now I'll probably get attacked by forum members and wanna be engineers about how xW30 oil is better and xW30 oil's HTHS, MOFT numbers, CAFE, engine spec'd differently in other countries, etc. While it does matters somewhat, again it doesn't mean 0W20 is a bad oil grade and it is not protecting your engine properly or that x30 will protect better. In some instances but not all, going to a higher grade may cause more wear. Especially with VVT. The oil won't form a consistent lubricating film, allowing metal-to-metal contact and wear. If an engine was designed specifically to use a lower-viscosity 0W-20, its lower viscosity allows it to flow faster and fill the tiny clearances between parts, leading to a durable, consistent lubricating film. Yes I know there are engines in the US that are overseas and is spec'd differently in other countries but who's to say the ECM is not programmed differently or they use a that different VCT (cam phaser) calibrated to that weight of oil? In the beginning W20 was primarily for CAFE regulations but it's been almost or over 20 years since then. To say it is strictly CAFE related nowadays is not entirely true. Most likely going to a x30W for an engine spec'd for a 0W20 oil will not harm anything but the argument that a x30 oil will protect better, I don't buy it. I have used 0W20 oil on my cars that are spec'd for 0W20 and conducted oil analysis with no issues. 0W20 is a robust and synthetic oil that will protect your engine. At the end of the day do you and do the research. You will see many on this forum that will tell you 0W20 is great oil and vehicles with 200,000+ miles on their car using 0W20.