Which oil to use for transmission?

hi everybody,
Ive just bought an 93 model Vespa Px 200. Ive been told to use the same oil for my transmission which I use for my engine. But Ive seen in web that some people advicing to use SAE 30 oil for transmission. I`m using Castrol TTS for the engine. What should I use??
Thanks in advance,
Gokce.

Thanks guys,

I will change it to SAE 30 oil for transmission. Ive talked with the mechanic and he said that piaggio told them to do so. And almost all the people having vespas using two stroke engine oils for transmission here in Turkey…

Don`t put two-stoke oil in the transmission! SAE 30 is the recommended weight but you can get away with using bog standard cheapo car oil like 30-50. I have been for many years with no noticeable side-effects.

[:smokin:] I dont know about everybody else but Ive had good results using Motul Scooter 2T for the engine oil and Motul 2T Transoil for the box - they both work great.