Here is everything i have already found out, going into a bit of detail about the different oils. yea ive already spoken to tim at opie, and he suggested either 70w80 or 75w90, so that doesnt clear anything up. VWs original spec was for a 75w90 mineral oil which has viscoisities at various temperatures very similar to redline mtl, which is a 70w80 synthetic but much the same characteristics as the mineral vw stuff original to this box (which vw dont make any more) but then this VW reccomendation was changed to a newer much thinner synthetic. G52. Then G60. Then G70. each time becoming a little