We bought the 2001 Z28 used and are going to change the oil this weekend. We used Mobil 1 from the start with the 2002 SS. But since we bought the 2001 we don’t know if you can use synthetic oil after conventional oil has been used. Can or would it make a difference switching from conventional to synthetic oil. If it would make a difference what synthetic oil is better to use: Mobil 1 or Royal Purple? Thank you for any comments and advice!

 

yes, no harm in switching. an old rumor is if you switch from synth. to dino oil, it will gell up in the engine. thats not true either. i dont know what happens if you add slick 50 or equal to sythetic. probably nothing but im not willing to try it.

 

I found I used oil when running synth and didn't use any when running conventional.

 

I have always had fine luck with conventional oil, as long as it is changed periodically. Pennzoil & Wolf's Head are my picks. (Actually they're the same company)

 

Same here. I think it's from the oil being thinner, so it can get through seals a little bit.