Originally Posted by cossie604

If this is becuase you have stripped the threads then the easiest repair is to buy a m16 tap and a suitable drill bit and re-thread it to this size then buy a peugeot sump plig that is visualy the same as a standard cossie bung ie 13mm hex but with a 16m thread over a standard 14mm. Shouldnt be any need to go bigger in the spanner size for a sump plug if your torquing it up correctly....vauxhalls use a T45 torx and they do just fine if not over tightened and thats alot smaller than a 13mm spanner.