i based my answer on this quote from edmunds.com and asking at tire/wheel stores http://www.edmunds.com/driving-tips/...a-primer.html:
"Two kinds of zero-pressure tires exist in the market today. Both types still require the usual amount of air to provide day-to-day performance.
Self-supporting tires (SSTs) are the original and most common run-flat type. Heavily reinforced sidewalls support the vehicle after air departs the scene. This sort of run-flat is designed to fit on normal wheels with no modifications
Michelin's PAX, a patented auxiliary support run-flat system, is a relative newcomer. PAX sidewalls, while still stiffer than normal tires, are not as rigid as SSTs. Instead Michelin designed a unique wheel that positions a semi-rigid "support ring" inside the tire to hold the car up when the air goes bye-bye. A non-standard bead design is necessary where wheel and tire meet."
no PAX tires are curently available that i could find in the usa
also, 2 different tire stores said they can mount run-flats on my 1997 pickup truck, built before run-flats were commonly available