Why does it matter though? They're used for different orders of magnitude. I've never understood why people think that having everything in multiples of 1000 (as the metric system does) is an advantage. Yes it's easy to say how many millimetres there are in a kilometer. But when was the last time that came in handy?
That said, I think the US car industry has moved to metric and it is great to not need multiple sets of everything.
That said, I think the US car industry has moved to metric and it is great to not need multiple sets of everything.