I want to ask a question, be it dumb or not, why is it that my dad and I have noticed a huge difference swapping from Dino to Synthetic. Let me explain, after 2 oci's with synthectic the car's feel alot "looser" or "smoother". Could this be that synthetics have an add pack that cleans the engine, are synthetics thinner than Dino therefore getting into all of the nooks and cranny's and cleaning out all of the old oil? On my car I'm running Mobil1 10w 30 at 3k OCI, and on my dads van I'm running Mobil1 5w 30 at a 5k OCI. Is this typical for synthetics?