I don't know about your Wally World but ours replaced the Mobile 1 V-twin with Castrol V-twin full syn. 20-50. I haven't used it yet but I know guys that have been using Castrol in their Harley for more then 40 years and don't have anything bad to say about it.
Funny thing is I can't find the full Syn. on Castrol's web page either. I just went out the garage to make sure I didn't misread the label but it says Full Synthetic. Hmmm.... Maybe it's new. I haven't used it yet so I don't have much input on the quality. IMHO good brand name oils changed every 3000 miles and maintained proper levels is the key.I asked but the syn. Castrol isn't in Canada yet, you know we're so far away.
Smitty,here in Canada Deeley regulates what the dealers sell and they frown upon coming upon a dealership that stocks anything but HD oils.
Anything else and they won't get their % for the sale.
Most dealers do not agree with this and are quite happy to put whatever oil in your ride that you provide for them