That theory is in fact out there and wide spread. I've also heard that it was part of a disinformation campaign by Mobil when they simply couldn't compete with synthetic oil makers. To go with that story I've been told that Amsoil engineers got so tired of dealing with the bad press of failed Mobil synthetics that they went to Mobil and provided information on making a better product. For what it is worth, Amsoil has been promoting extended oil change intervals for almost 40 years while everyone else is sticking with 3000 miles. It's only been in the last decade or so that oil manufacturers (Mobil specifically) and OEMs have started increasing the service interval. The OEM argument being that you have to provide guidance according to the lowest available common technology - knowing and excepting that some owners will be cheap, use crappy oil and miss oils changes and then blame the OEM for having a crappy product.
I think the only reasonable time when the leak theory might hold water is in the case that a rubber (not silicone) gasket has been in service for a while. Depending on the additives maybe the rubber swells or looses adhesion. Every head gasket and exhaust gasket I've ever seen are metal/lead, that leaves timing cover, valve cover, and oil pan as oil exposed gaskets. Not really pressurized and often times as easy to fix as torquing the bolts - also hard to blame on the oil. YMMV Josh On Sat, Aug 31, 2019, 1:37 PM Ronald B. Frerker via CnC-List < [email protected]> wrote: > I'd been told by a mechanic, that one shouldn't put 100% synthetic oil in > an old vehicle that had been using regular oil all its life. The claim was > that it would clean the engine too good and it would start leaking. > It's highly recommended for newer cars of course. > I would presume the same would be true for marine engines, unless the fact > that they're diesels would make a difference??? > Anyone else ever heard that story and have heard whether it's true or not? > Ron > Wild Cheri > C&C 30-1 > STL > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > >
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
