So, Honda, unlike Ford, isn't claiming that 5w-20 is actually better than thicker oils.
Honda clearly states that it's done for fuel economy only.
From that article:
"Unlike Ford, Honda's owner's manual includes a statement that if 5W-20 is not available, 5w-30 is acceptable - but the next oil change should be 5W-20.
In addition to assuring itself that the claimed fuel efficiency benefits for 5W-20 were real, EPA was concerned that customers actually use the new oil and there be adequate supplies to meet marketplace demand.
Ford's unambiqious owner's manual message to use 5W-20, without recourse to an alternative oil like 5W-30, is as strong a message as we could reasonably make to our customers in promoting this new oil."
Conclusion: 5W-20's are here to improve fuel economy (marginally) to satisfy CAFE or to promote "Green" image.
They don't provide any extra protection or durability, but do provide adequate protection for an average consumer.
Europe so far stays away from thinner oils.
To improve fuel economy they utilize more effective solutions like smaller cars with smaller engines and diesels.
[ June 19, 2006, 08:05 PM: Message edited by: vad ]