This gearbox comes primed i.e. it has some oil in it but you will need to top up the tank to the correct level after you fit it. They used to say use 10W/30. This is no longer the case the oil in the box is 5W50 fully synthetic. It is very expensive and you will only need about 1 litre. We can not ship oil but you should be able to get this from your local car spares place as it is the same oil they use in the engines of BMW and Mercedes. YOU CANNOT MIX OILS, please only top it up with the oil as mentioned otherwise you will blow the transmission, and nobody wants that to happen.