what size is the hex on the oil drain plug?

[TFitch]

OK, after my last post I was ready to change the oil. Fool that I was, I assumed the manual would tell me the oil capacity.    OH NO... just take it to your mini dealer and have them do it!!

So, I assume that the 09 mini takes 5 quarts.    I have 5W30 Castrol, which is what the dealer told me was recommended.  I belly flopped to get under the baby with sockets in hand.  Lo and behold, it looks like it will take a hex.  Before I go to the store to buy a hex socket, can anyone tell me what size it is?  I had a 7mm, but it was too small.  Since the store is 30 minutes away, I'd like to know what I'm going after.

Thanks for your help.

[MPlayle]

I use an 8mm allen wrench to remove the drain plug on my 08 Clubman-S.  The oil filter should come with a new o-ring for the canister and a new crush washer for the drain plug.  I forgot to check the exact size for the socket to remove the canister, but I believe it is 27mm.

I usually find my MINI wants 5.5 quarts of oil with a filter change.  The capacity is listed as 5 quarts - hidden in the tech section of the owner's manual, takes a bit to find it.  I add the full 5 quarts, run the engine for about 30 seconds to establish pressure and fill the filter.  Then I let it sit for about 1 minute or so and check the level on the dip stick.  I found it seems best if filled to cover to the top bulge of the measuring zone.  That may be a little over-full, but I don't get any "rattle" on cold starts after sitting overnight.