I'm starting to get that concept now and it's really not all that hard to grasp once you realize metric is more precise than American Standard.

For me it got started one day when I was at the Ford dealer getting parts to restore my Mustang. They had ordered a speedo for someone and received the metric one. The only difference in the part numbers between the MPH speedo and the KM/H speedo was ONE number. So they sold it to me for $25US and since it would fit my car, I thought why not?

It throws off anybody that drives my car now. They're poking along thinking they're doing the posted mph speed limit when they're actually doing km/h.