[wagonman76]

Guess I jinxed myself. Woke up to -25F this morning. Took 10 miles for the mpguino display to fully show up.

I have always understood that conventional oil should be used for break-in too, and changed soon.

But as far as what GM recommends for normal use, I wouldn't necessarily consider that to be the best. They want you to use something that is going to get you just past the warranty period.