OK, so I did as I was told here, and looked up the handbook for the spec. Armed with said spec - I toddled off to SuperCheaper to buy some oil.

I found myself faced with 100's of different oils - none of which said anything about the required spec.

Penlite Ready Reconner did suggest one oil - but they only had a 5 L bottle, ie 10x what I required.

So I went to my local dealer - who topped it up at no charge. The oil they use is "Castrol EDGE Professional C1 5w-30".

My vehicle is serviced at rough 10,000 km intervals and its due for a service. I didn't have time to get that done before and unexpected trip. The oil level sensor thingy said that it needed 500 ml - so I had it topped up. Never done that before.