I'm inclined to agree and if something happens with the transmission and you used something different than DW-1, Honda and other transmission mechanics might point that out - and there's nothing you can respond with? I bought ATF that someone had extra of and that was my only concern - it was DW1 but was not 'new' or recent. I am considering doing a 4th drain and fill of brand new fluid later - after it's used - just for peace of mind. DW-1 here is probably cheaper than the alternatives - it's really expensive on Amazon and I don't know that anyone around here supplies Idemitsu either. I think Idemitsu is carried by some places in Japan as an alternative to DW-1 but I think it's kind of odd - when did it start and is there any real recent comparisons between the two to confirm it's good and that Honda will accept it as a usable alternative? I don't think it's available in every country either - either has to be ordered on Amazon or Ebay? Okay, sorry for rambling.
Edit: Found this:
https://oilsadvisor.com/honda-atf-dw1-equivalent/
We've pretty much beat the topic to death in a couple places on here. You can't go wrong with real DW1, but you probably won't go wrong with the others as well.
That website you linked though, is a mess. I wouldn't take any of that information into account. It looks like they just copied text right off the bottles. It almost reads like a Project Farm video.
"So, what are the negatives of using Idemitsu’s ATF Type-H Plus?
The lifespan of the Idemitsu ATF is a little bit shorter than that of the ATF DW-1, and the price difference it brings might not make up for the same, in most cases. "
Wha? Not sure where they get that from.
They also claim Z1 was pulled because it caused cancer or some such nonsense. Z1 was pulled because the base oil was pretty shear prone. DW1 is essentially the same additive package with a better base oil. That's all there is to that one.
One more:
"LubeGard’s
OEM comparison chart shows that both Red and Platinum products are a viable replacement for Honda’s DW1. The Red is more affordable than the Platinum. "
Again....wha? Lubegard is an additive, not an ATF.
That article is complete trash.
Here is the discussion in the white papers section where we get a bit more into some Honda history:
Three ATF's were analyzed by two labs, one a university lab and another a commercial lab to determine their elemental and chemical composition because of on-going debates about the suitability of each fluid for various applications. The three ATF's analyzed were: Genuine Honda DW-1, Valvoline...
bobistheoilguy.com