I did look on opie oils and said the same as yours but looked at the book and the book said 75w/90 all round but never said semi or full, then i had a look over the road and the oilman told someone the same 75w/90 full all round, its doing me head in now, was going to buy the other morning when i got me engine oil, but have left it now till i get a average answer before i change, as ive neglected them oops