Fuel economy measures how efficiently a vehicle uses fuel to travel a certain distance, typically expressed in miles per gallon (mpg) or liters per 100 km.

1 cosmo = 1.0829e-52 1/m^2; The "cosmo" represents the cosmological constant. It is a dimensionless quantity denoting the energy density of empty space. (review pending)

1 mpg = 425143.7 1/m^2; "MPG", or miles per gallon, is a unit of measurement used to determine the fuel efficiency of a vehicle. It represents the distance in miles a vehicle can travel on one gallon of fuel.