I wasnt sure if this is the spot or not so if it is not I am sorry. I have a 1999 Z28 and it has about 56k miles on it. I bought it used and the person used Castrol 5w30 regular oil. Would it benefit me to switch over to a synthetic or synthetic blend?? I heard that an old engine can not be switched because the synthetic is thiner and will leak through the rings?

 

You will not have any problem, switching to synthetics. I would even recommend going to a 5w-20 weight oil. It sounds like the person that owned the car, maintained it well.

 

Thanks!!