I made the decision to switch from dino to synthetic in my 1998 Camry with 72,000+ miles. Although I have not seen any indication of sludge, I want to avoid it. I have been reading here and on another board to help me make the decision. The other board has a post recommending that if you make the change from dino to synthetic, you should first switch to a semi synthetic for one or two oil changes to help the engine make the transition. Then, switch to a full synthetic. I have not seen that even mentioned here. Is there any truth to this suggestion?