Terms Used and Calculations Made
The following definitions apply to the discussion here:
- Energy is measured in British thermal units (BTU).
- A passenger-mile traveled is one passenger transported one mile.
- A ton-mile is one ton transported one mile.
- Passenger energy efficiency is the ratio of passenger miles traveled to BTU (or to energy consumed).
- Freight energy efficiency is the ratio of ton-miles to BTU (or to energy consumed).
- Fuel economy is the ratio of miles per gallon of fuel.