If you search the forum, I think general recommendation is any oil that conforms to 5w30 A1 (A1=fuel saving) spec. It is normally a fully synthetic oil.
fwiw, I personally use thicker Shell Helix HX7 10w40 A3 (A3=performance) semi-synthetic. (Honda dealer apparently used Shell 10w40 on 2nd and 3rd year service) I did try Castrol Magnatec 10w40 A3 semi synthetic once but felt exhaust sounded rough on idle, so returned to using Shell. £19 or less from Carparts4less.
Requires 3.6 Litres.