Chemical equilibrium? WHAAaa? Does this apply Le Chatelier principle or something? lol From my understaning, syn basestocks
cause seal shrinkage. When syn oils came out back in the day, the additives used were not sufficient in addressing the seal shrinkage, hence many vehicles leaked. However today's oil manufacturers are using hte proper additives to
address the seak and gasket issues. In fact, I believe syn oils better swell seals to fit better than petro oil.
Back to your question, from reading several surveys regarding switching to synthetic oil, the approach of guesstimation is very inconsistent here. It is tested, that vehicles w/ higher mileage are more prone to leaking. On vehicles that have seen petro oils for a long period, the seals and gaskets become dry and cracked, however leaks aren't seen due to the sludge that coats the
cracks. This sludge is just the burn off of petroleum. Hence, when we use syn oil, the detergent cleans these seals off. So for those who experience the leaks, this is simply due to this. However, keep in mind that the additives I spoke of earlier
help allow the seals to swell to limit leakage.
I, personally switched at somewhere around 46k w/o any issues. One thing I did note about my vehicle which is strictly empirical is that I consumed a lot more oil initially w/synthetic than dino. Anyways, it's really up to you. If you are generally easy on the car, not taking it too hard, then stay w/the general dino oils (Any major name brand dino oil
will do--I think it was beachboy w/something near 200k miles w/dino!). But do keep in mind that it was something like 95% of vehicles do not leak when switching to synthetics. Good luck w/whichever course you take.
