regular/synthetic mixing

If I mixed in a couple quarts synthetic in my next oil change and topped up during the season with synthetic oil, would there be any benefit to engine life or lubrication? I put in regular castrol 20-50 at last oil change. Maybe this would be a cheap way to get synthetic oil benefits? I read the archives that say they can be mixed. Do you think it is a good idea or a waste of time?

from what i udnerstand, it won't hurt anything but you won't be getting the full benefits of synthetic. as long as the weights are the same, you should be okay. offhand i asked a few mechanics the exact same thing and i'm just relaying to you what they told me.

jury: waste of money, go full one way or the other

obin