oil for jetta 1.8t

im using just regular castrol oil but was woundering if i should switch to syncentic my car is auto and has 78,000miles?

Your choice on that one. I'm going synthetic Castrol Syntec 5w 30 on my 2.0 when i do my 80,000 which is about 3k from now. Just took a trip and only got 25 mpg, was around 30 mpg. With the 80,000 i will change the plugs, plug wires, air cleaner and fuel filter as well as synthetic oil change. Can't wait to see and feel the difference.
Franco

Asking whether to use petro or synthetic oil is like asking about politics or religion. I use what I use. Others can use what they like.