I've read that the PT engine (even if it isn't a turbo) will last much longer using synthetic oil. "They" say that Chrysler didn't plan on us using synthetic....and that can help you keep the car much longer than the 5 year average.
(Of course Chrysler didn't want the engine to last tooooooo long)

That's why I have the GT vert garaged, and I'm drivin'
soonercruiser as my day car until I find a good, rich home for her!