[W126 Coupe] don't use high mileage oils

[Shayegan, Richard]

I e-mailed Pat Goss just to see what his thoughts were on going to a
thicker oil as a car ages. He said that he doesn't think it's a great
idea, and in fact he likes Benz's new recommendation for older cars too
(namely, 0w-40 synthetic). I asked him if he knew of a regular oil that
was 0-40 since I have a leaky rear main seal and don't fancy the idea of
synthetic all over my driveway. I mentioned that the rear main seal had
pretty much fixed itself after 2 years of high mileage oils though. Then
he told me that now that I've used high mileage oils, I have no choice,
I have to keep using them. He said unless an engine is in serious need
of seal swelling, don't do it, because it overswells the seals and then
the car becomes dependant on that extra swelling. He said I might be
able to still use regular oil since I'd only used the high mileage for
15,000 miles, but that even though it's only been 15,000 miles I may
still experience oil consumption if I go back to regular oil. I don't
know about y'all, but I hate the idea of being dependant on an oil,
especially one that only comes in 2 acceptable weights, so I thought I'd
give y'all a heads up.
Richard