synth vs. dino

[Amber Lamps]

I got this from Mobile1's website,


Can different synthetic motor oils be mixed together?

Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. However, it is important to note that the superior performance of Mobil 1 will be reduced by diluting it in any way.

They also dispute the need to breakin a motor using dino and the need to flush a motor before using synth. There wasn't any mention of flushing before going back to dino. Altho',I don't get why you'd want to flush out the good stuff before putting in the cheap crap. That'd be like making sure you rinse your glass before switching from Grey Goose to Heaven Hill!

Originally Posted by Trip

it has something to do with mineral oil coating being thicker than synthetic and the tolerances your engine develops running synthetic.

Um doesn't viscosity determine an oil's "thickness" and if so wouldn't ANY 10W40 oil be the same? I always thought the "superiority" of synth was it's ability to retain it's viscosity for longer under harsher conditions.