If that were true, ask them why Honda recommends its own HP4 synth blend oil in the 400EX owners manual??? Any JASO MA oil is compatible with a wet clutch, like on your 400EX. You do not want to run HP4M however, which has moly.

I have run various synths and synth blends in my 400EX for something like 5 years now.....still the original clutch.

 

thats good to know i will be running synthetics from now on. thanks

 

yeah, i have ran mobil 1 in my 400ex with a sparks clutch for a few years and i just checked the plates.... they looked like new.

 

Back a few years ago, HP4 and HP4M had virtually the same bottle (now they are thankfully different colors!). You had to look REAL carefully to see the words "with or without moly" on the bottles. It was REAL easy to make a mistake. I did once, and ran HP4M in my 300EX and 400EX for some time, with absolutely no ill effects. In fact, it may have done the 300 some good. They are famous for having "sticky" clutches. I think the moly loosend it up a little.

Like I said, I don't know why Honda HP4, HP4M, and GN4 are no longer API SG??? I would no longer run any of them!

Subjectively, I think I am seeing a slight increase in performance when I run Maxima Ultra. At first I thought it was just marketing hype, but I do think the difference is real. Keep in mind that this is just my "seat of the pants" opinion. It's not like I did before-and-after dynos, or anything like that.

If anybody thinks Ultra is expensive at $8 per liter (slightly bigger than an quart!), I was at Chaparral the other day and noticed they are charging $10 per quart for Mobil 1!