I just poured Idemitsu 0w-20 into a 2017 hatch and it is so smooth in ECON mode that I put it back in that mode when I took it out very briefly, yes I missed it that much in that brief of time. (I've run the car in ECON almost in its entirety and it was never this smooth with the P66 OEM)
Here are the pluses compared to the P66 Honda OEM it ran on for 15,000 miles.
1. It pours like liquid gold as it comes out. Then, The color on the stick is way lighter that you have to do a double-take to see if it is even on at first.
2. It is so smooth that it actually changes the way you drive. You drive slower when you aren't getting on it and it gives you smooth as a feature compared to the P66. And then when you get on it, it goes like a bat out of [censored] but it allows you to be more selective since you don't miss a thing with either driving style.
3. It fixed a warm start grind and this makes it so special, you wouldn't believe. And it is consistent with the fix.
4. It stays light even after 100s of miles. Very unlike the P66 OEM.
5. neither P66 nor the Idemitsu used any oil so no harm there.
6. Lower cold start RPMs (This should be #1 on this list cause it's the first thing I continue to notice, day in day out)
7. Faster at getting RPMs down on first start (This should be #2 on this list cause it's the first thing I continue to notice, day in day out)
8. Did I mention how smooth or how much smoother compared to OEM P66?
9. Quieter on start but esp once warm.