I've had some cold lifter tap in my Honda which goes away when warm. (Yeah, I've adjusted the valves a couple of times and it goes away when I set 'em tight, but I got too nervous about burning a valve so I set them back to spec) I've found Pennzoil Platinum 5w30 does the best at quieting that down...
Personally, I don't think I'd go as far as a 40 wt in an engine calling for 20 wt. but I suspect you're right about it making it quieter!
Personally, I don't think I'd go as far as a 40 wt in an engine calling for 20 wt. but I suspect you're right about it making it quieter!