i think probably 10W50 mate although if you're not quite sure i'd ring opie oils. if going fully synthetic make sure its ester based otherwise its at best a semi-synthetic even if the bottle is lables as fully sunthetic.

for my 2l n/a focus i'll be going for http://www.opieoils.co.uk/p-68896-fu...ngine-oil.aspx

as the internals are standard i feel the standard grade is required but as i use it on track days the additional stability and ability to cope with sustained raised temps the ester based fully synthetic is going to be better for me. if i had a turbo i'd be going for something thicker.