Deal All, I have a 1999 (T reg) Vauxhall Vectra 2.0DTI Estate, and wanted to do a quick oil change & filter. Having removed the Ecotec engine plastic housing to get to the oil filter, I was confronted by a massive nut that needs shifting to get to the said filter. Any ideas what size this bolt is? I'll need to get the socket for this as I have not got one this big! Thanks in advance Mika