I currently have 15w40 rotella in the sump and previous fill was 10w40 m1 4T. In the morning I usually have very little time to warm up the bike (10-15 seconds of idle before i'm in gear and rolling. For about the first 2 minutes or so of my ride shifting is quite stiff/rough and my clutch drags slightly. This was less noticeable with the 10w40 but still annoying - 15w40 is even worse.
Does anybody have any experience with M1 0w40 in a shared sump bike? I have 13 gallons of the stuff and really want to try in in the bike.
My main concern however is how will it hold up shear wise.