Can you tell me what kind of hub (transmission) oil you used? All the manual says is "SAE 90". I have some Mobil 1 75W-90 Synthetic Gear Lubricant I used with my previous Chinese scooter. Do you (or any other interested/knowledgeable readers) have an opinion as to whether that's an appropriate fluid to use here (on the GTi300)? If not, what suggestions do people have?