First, I'd like to know what dino oil is available in 5W-50 and 10W-60. Castrol offers both only in synthetic here.
Can forum members outside of North America tell us what Honda recommends for current models. I'll bet that 5W-20 is specified only in NA for CAFE reasons. The car companies treat North American customers like morons. We are too stupid to look at a temperature chart. Just tell them one weight, otherwise they, or even the dealer, won't be able to figure it out.
Audi, BMW, Volvo, and the like may go too far in the other extreme with overly complcated viscosity charts.