Well I too own a 2001 Taurus with the Vulcan engine. It has 90K miles and does not use any oil in between changes.
I bought it used at a dealereship, so I can't say for sure what oil was in it when I bought it.
After owning it for about 6 months, I changed the oil. I used Valvoline 5W20.
Why would you use a thicker oil, like 10W30 (well it's thicker when cold). I mean these engines are pretty tight, and if it's not using any oil then it probably is tighgt in there.
10W30 is thicker on start up so it won't flow as well. Oh yea it's also thicker when warm.
What made you go with 10W30?