Portland is a PR machine for light rail & streetcar

Here are Some Facts About Portland Oregon          

 

A value of 125,000 (a) is generally used as the heat content of one gallon of gasoline. (138,700 for Diesel)

 

If one gallon takes you 10 miles, then each mile required 1/10 of a gallon.

 

Expressed as an equation (Applying rules of fractions to the units):

 

 

                                         BTU per gallon

BTU per vehicle-mile =   ------------------------------

                                   vehicle-miles per gallon

 

Next you can adjust for more than one passenger. (The driver of a car is a passenger, the bus driver is not):

 

                                       BTU per vehicle-mile  

BTU per passenger-mile  =  ------------------------------

                                       passengers per vehicle

 

For 32 MPG:

125,000 / 32=3,906 per vehicle mile

3,906 / 1.2 passengers = 3,255 BTU per passenger-mile

 

For 60 MPG:

 

125,000 / 60 = 2,083 BTU per vehicle mile

2,083 / 2 passengers = 1,042 BTU per passenger-mile

 

Analysing Trimet's claimed mileage for cars and SUVs:

 

14 mpg:

125,000 divided by 14  mpg =  8,928 BTU per vehicle-mile.  8,928 / 8,150 = 1.10 passengers

 

17 mpg:

125,000 divided by 17 mpg =  7,352BTU per vehicle-mile.  7,352 / 6,712  = 1.19 passengers

 

a. Some sources show gasoline at 123,976 BTU/gal. (this is a difference of about 0.8%)

How to calculate BTU per passenger mile from miles per gallon