..should the fuel price measurement be $/metric tonne (1000kg) regardless of if you have metric or imperial units selected?
To remove confusions when talking of fuel prices.
Just have it indexed and then convert to kg or lb using the index (have it displayed in smaller font below the index). Then when someone says fuel is at 1000, you don't have people confused saying it's only at 400 for their airline.
You could set the index so $300/kg = 100. When fuel is $1000/kg in MT it will be 3+ and when the game starts in DOTM it is 0.4 or so.
A label I never understood fully on the stats page was "Average Total Fuel Burn (x1000)". x1000 of what? Instead of "tonnes (kg)" it would be better if it just read "metric tonnes".