You guys are doing a bigger disfavor to your engine by introducing a large airpocket. There is very little
oil capacity % wise in the cooler. You change your
oil too frequntly anyway. You can never get all the
oil out of a motor anyhow when changing it. If that last 1/2 quart is such a big deal, then right after changing the oil, why does it look so fresh and yellow? I am yet to hear why it is bad to mix viscosities of oil, in an engine, from an engine builder. I think it's more important to just have fresh oil that is warm. Keep it yellow, and let it get hot before you stand on the loud pedal.