If your ordering from tirerack (only US supplier I believe) they will send you the correct lug nuts with the wheels. Look like a 45 degree taper to me. I have a few extras and can take a closer look when I get home. IIRC fiero lugs nuts also fit but I'd have to double check to be positive.
The fiero lug wrench will not work for these wheels either. Their design leaves little room around the lugs. Make sure to carry a rachet/breaker bar and socket with your spare. I keep a cordless impact wrench with mine.
EDIT: 60 degree conical taper. 19mm, 12mm x 1.5 thread, 1.5" long.
[This message has been edited by Fieroseverywhere (edited 10-05-2010).]
