On my 156, the sump bolt on my internal socket is a bit loose where the torx socket goes in so i ordered a new one off ebay delivered to Australia from England for $26, it was a genuine part from a English Alfa Dealer, upon checking it i noticed the torx socket wouldn't go in as now it is a 8mm [5 /16 inch] hexagonal internal socket, thinking what a goose for using the wrong tool, i noticed the old one was most definately a torx fitting, but you could also use a internal hex in it!, go figure, whats the story?, Colin.
ColCol, I've always used an 8mm hex in mine, although I can't be sure I've ever had a really hard look into the bolt to see..
same here, definitely 8mm hex for the JTS