what oil is the best to use then
I’ve no idea whats “best”… I use Pedros Synlube as I have a little bottle of it and no longer use it on my chains.
I worked my way down to oil, started with normal grease which makes the hub quieter but can stop the pawls working if you put too much in, and also makes the freehub mechanism a bit sticky and hence less willing to freewheel (especially when in very cold “freezing” temperatures), next up was Manitou M-prep which being a very light grease I thought would work well but it sort of turns to liquid and tended to freeze worse than normal grease (High water/liquid content???). Next up was the Synlube oil which I’ve been very happy with, makes the hub much quieter and freewheels much better… and importantly doesn’t freeze or get sticky when taken out in very cold conditions. After a few months it gets noiser and needs a top up, which is piss easy.