[darrin]

Originally Posted by HarryD

No really. If you want to try one, why not.

When synthetic oils were first introduced, they lacked an additive that caused some types of rubber seals to swell like the Dino oils. As a result, there were numerous reports of excessive oil leaking when you switched from a dino to syn oil. Since that time, the oil makers wised up and added something to the syn oils swell the seals. At this time you "should" be able to switch back in forth but as in all things YMMV.

Thanks Harry!