25W50 Oil

[cinquecento]

Castrol Market a 25W50 fully synthetic oil ( as well as 10W60). Any feedback if the 25W50 would be suitable for a Sydney based 96 Griff 500 (PS and AC) where winter temps are rarely below 10 deg C (maybe 45 Deg F) and Summer days are often over 30DegC +.

Thanks