Do a google search you will find it sold online, its ridicolously high priced. I thought Royal Purple XPR was exspensive at $15 per qt, this stuff runs about $18. Not worth it at all unless your a total M1 buff.
RP XPR has ZDDP in the high teen range which is more than enough for any street vehicle. But again, if your a M1 buff, then by all means. I for one, don't like to mix oils. Even of the same brand. Thats just me. Im no chemist. haha.
Jeff