iirc it is 6X140mm, some newer 6X5.5" lug wheels also fit but the center hub is larger than most newer wheels. i know that the early 2000's toyota 6 lug trucks have the same pattern but i never got around to test fitting any wheels.
this thread may be of some help:
http://www.mazdarepu.com/board/viewt...?FID=8&TID=758