Someone just told me it's a bad idea to go back from synt oil to some regular or synt blend?
why is that ?

 

It used to be that way in the early days of synthetics, as the early form of synthetics were not compatable with conventional oils, and problems with the seals occured also. But with modern oils, there is no problem whatsoever switching back and forth as many times as you wish.

 

great !
Thanks !