I'm thinking fiction. What IS different is the plastic center caps . . . they look identical but you can't tighten the steel wheel version down on the aluminum wheels because the little plastic lug-nut simulators won't reach. If you use the Aluminum wheel caps on steel wheels they rattle because the similators bottom out before the cap is really tight. This could explain why somebody thinks the lugnuts are different. What's really different is the thickness of the wheel flanges.