When to switch to synthetic oil?

[nsmitchell]

Originally Posted by jdomville

When you take any TOYOTA to the dealer for service you will get the same oil as was in the car at the factory. No matter what it sayes on the can (Toyota Oil) it is MOBILE One.
So "Changing to Mobile One" is no big deal. The car had it in it originally and still does unless you foolishly swiitched to something else.
Keeping Mobile One in the vehicle is certainly in step with the warentee besides being the best thing you can do for the long life of the engine. Make sure the filter has a check valve built in it.

So you are saying that Toyota uses Mobil-1 for all their oil changes?! That is great news, but how do you know this to be true? Mobil-1 is soooo much more expensive than conventional oils, but it could be the secret behind Toyota's legendary engine longevity. Hmmm. Please show me some proof. Thanks!