The reason I ask this question...I've been working in the high-end European car market for over 20 years. Like many enthusiasts, they love their rides and maintain them meticulously. And it isn't unusual for many of them to pursue the latest & greatest German-made motor oils (eg: LiquiMoly, Ravenol, Pentosin, ect.). So, do the same habits occur among Honda owners?
The most common Japanese oil brands available in N. America are Idemitsu and Eneos. Many of their products are used as "factory fill" for several Asian auto manufacturers and most likely used during R&D. According to independent VOAs, Japanese oil blenders tend to use higher amounts of anti-wear additives in stout base oils to achieve performance/fuel economy goals. Interesting to note that both manufactures were also instrumental in the development of the low viscosity motor oils that are so common today. I've been using Idemitsu 0W20 full synthetic GF-6/SP in my K24 @5-6k OCIs and couldn't be happier. Even @ over 150k miles, I can still exceed the manufacturer's fuel economy standards with some conservative highway driving.

 

No need to mess with overthinking oil brands, use the correct grade from any brand sold here in the U.S. and the engine should outlast the rest of the car.

 

Agreed, no one should ever experience a lubrication failure with almost any API certified motor oil, even conventional oils(w/shorter OCIs). I guess my inquiry was aimed more toward the discerning enthusiasts who often "overthink" almost anything when it comes their vehicles. For example, the Eneos brand has developed quite a following in the Subaru community. We use it in every Subaru that we've serviced and have actually had return customers because of it. Call it the "placebo effect" or simply 'piece of mind', using an engine oil engineered/produced from a vehicle's country of origin is desirable to some.

There's also this dyno test from a few years ago where Idemitsu w/high moly made a substantial difference in a k20 Civic, so no smoke-n-mirrors here.

 

So here's my standard response for folks who overthink oil, "Oil is like religion, use whichever brand and grade you worship; in the end it will make no difference to the life of the engine."