Video Games are full of smoke & mirrors. When you present the data to the player, add km/s at the end of the string - they will never know. The same goes for distances - no game ever deals with an actual galaxy far, far away. You tell the player the cargo is 12 parsecs away and they must believe it.
But yes, you could (and probably should) write a couple of functions and pipe the engine’s internal data - have the formatted values come out on the other end as you see fit.