ON THE ROAD Praxair is revving up sales of hydrogen which refiners use to produce cleaner-burning gasoline. And, who knows? Down the road we could be driving hydrogen-fueled vehicles — the ultimate, environmentally friendly fuel. Praxair is supporting research projects that may make that happen. In addition, argon, nitrogen, oxygen, helium, specialty gases and surface coatings comprise a significant portion of indirect materials used to produce a variety of vehicles.