I have just picked up the newly published Haynes Manual that covers the last of the Vectra mk1's ie up to May 2002.

In there it suggests that if you have a Vectra with an F23 gearbox that you should overfill it above the level plug by about a pint as this is a modification that the main dealer should have made at the first service (or words to that effect) .

Anyone know why this is and if it applies to all F23's as I think some are fitted in petrols and others to diesels.