There shouldn't be any steel touching the aluminum wheel if the valve stem is installed correctly. But when you have to figure that putting these together, it isn't a high skill job and that's where the last guy hired gets his first upgrade from floor sweeper.
Then there is the problem of wheels 'welded' to iron hubs, especially after a year or so in the rus/salt belt - but the steel lug nuts are never a problem.
Conundrums abound
