Me and the missus did Montana/Wyoming/S.Dakota in June last year going to Rushmore. 105 in Buffalo and Cody. I run the hondaline 10-40. No problems....with the oil......Planning a coast-to-coast and back ride next late July (2014) from Olympia to New York across Canada, back on I-80 through Sturgis and then home. I'll be using synthetic (probably Amsoil). 10-40 or 20-50? Three weeks.
1985 GL 1200i.
That would be me. $12 for a jug $3-$5 for a filter $1 for a tub. Less than $20 to keep those hydraulic valve tappets from getting plugged up by the junk in the oil and causing the valves to tap and the clutch to shift hard and other engine wear.many folks really like the DELO/Delvac 15/40 oils. Very reasonable price and excellent protection.
I want the Amsoil synthetic for the fact I won't have to change oil along the way. Threads and posts here say it will go 8,000. I'll have the engine cleaned out (as I did at 26K) and use an AMS filter. I have being using another synthetic and the machine simply shifts cleaner with no false neutrals. That alone sold me on synthetics.Then you should have asked a question about religion, or politics, rather than oil..........
10/40 will do just fine. You have three weeks, so you won't need racing oil.