Synth blends [Was: Re: Warming up engine]

[Elliott Potter <epotter@abraxis.com>]

This talk of oil and warming up the engine brought up a question I had. 
My car has been dealer serviced all its life, but now that the free
service has expired I'm going to go ahead and do some stuff myself, such
as changing the oil.  Now being a poor college student I can't really
afford synthetic oil, but I wanted to try some synthetic blend.  Less
expensive than full synthetic, but (at least I think) at least a little
better than regular dino oil in the cold.  The thing that prompted me to
even think about this was the *horrible* valve racket the V6 makes when
it's 20F or so outside and I start it.
So anyway, I get the stuff, and my dad sees it (oops) and says "are you
kidding?  Take this stuff back, it will ruin your engine!"  I had never
heard this before, and on more prompting he said that if the synthetic
oil mixes with the dino oil left in the crankcase, it will turn to
sludge and ruin my engine.  I'd never heard that before, and politely
(so I thought) pointed out to him that synthetic *blend* implies that
it's already mixed with dino oil, but to no avail.  The compromise was
that I'd ask someone knowledgeable about it and make sure that it
wouldn't screw anything up.

So who is more knowledgeable than you guys?

Anyway, all I need is for someone to say "no this won't screw up your
engine" so I can change my rapidly darkening oil.

I hope that this doesn't start another aweful thread about the relative
merits of different oils!  All I need is "this will hurt" or "this will
not hurt."

TIA!

Elliott

"Et in Arcadia sum?"