I know oils have been a much discussed issue, so apologies if this has been answered before. I have looked in the official Ducati workshop manual for my newly acquired 750F1. It states the engine oil should be Castrol GTX2 - turbo tested - SAE 20W/50 or equivalent. As its a 1986 engine I'm guessing this has long been out of production, and a google search reveals no useful information. It is clearly different from Castrol GTX, but does anybody know what it was? The current Castrol website reveals; Castrol recommends for your Ducati 750 (1985-2002) Power 1 Racing 4T 10W-40 Should I go for that, or a 20W/50 and if so what grade?