[Mauzen]

You could just remove the the last one:

format(String,sizeof(String),"~r~Fuel~g~:~p~%d ~r~MPH~g~:~p~%i",CarFuel[vehicle], floatround(floatdiv(Speed, 1.609344), floatround_floor));

But if Im right, you want to show both MPH and KMH, then you need to add the KMH to the string like this:

format(String,sizeof(String),"~r~Fuel~g~:~p~%d ~r~MPH~g~:~p~%i ~r~KMH~g~:~p~%i",CarFuel[vehicle], floatround(floatdiv(Speed, 1.609344), floatround_floor), floatround(Speed, floatround_floor));