Do you think americans should also use SI-units? ——— Probably. I'm not sure if I'd ever get completely used to them, but I think the system is more logical/efficient and it's also more efficient to be streamlined with the rest of the world. And it's also more efficient to only have one system in the same country.. here there's two. Take tools, screws, etc. for example, some of them are sized in imperial units and some of them are sized in metric. Then there's 2-liter soda bottles, etc. etc. I think if Americans were rational they'd want to use the metric system and we'd be using it already.