Devon Aygo has recently supplied the following information on oil requirements: "The issues over which oils are used is caused by a European law called "Block exemption" the same law that states that manufacturers can't insist on main dealer servicing, also stops Toyota from insisting what oils are used by anyone wishing to service a car including their own dealer network. All Toyota are allowed to do is list a set of specifications that the oil used must meet they can also list a "preferred"