Because it is a sensible unit for measuring distances. It can be related easily to smaller units of distance - like a metre. And there are many crossovers to other measurement units in the SI system - for mass, force, etc.
Kilometers
Mostly Kilometers, for road signs etc...
Use this equation to convert miles to kilometers: miles x 1.60934 = kilometers
Usually, you would use kilometers.
The decision when to use kilometers and when to use meters is sort of arbitrary. But usually you would use kilometers when you expect the distance to be close to a kilometer, or larger than a kilometer. For example, distances between towns or cities are often expressed in kilometers.
kilometers
Kilometers
You would use meters because kilometers are about half a mile.
1 mile = 1.609344 km, use this conversion factor
How many kilometers per liter does Mitsubishi Fuso use
Use this equation: miles x 1.60934 = kilometers
Canada is on the metric system. Therefore, Canadians generally use 'kilometers'.