Paul Souders vs. a 2008 Subaru Forester

(A Quick Back-of-the-Envelope Calculation)

• P_m = price of a gallon of Alpenrose 2% milk at New Seasons = $3.89
• P_r = price of a gallon (16 cups) of cooked white rice at New Seasons^[1] = $0.35
• D_fg = mileage of our 2008 Subaru Forester (standard transmission) during a typical week of commuting = 24.5 mpg
• E_g = energy equivalent of a gallon of gasoline = 31,000 kcal (aka “calories”)
• E_m = energy equivalent of a gallon of 2% milk = 1952 kcal
• E_r = energy equivalent of a gallon (16 cups) of cooked white rice = 4256 kcal
• p = energy I burn in one hour riding my bike on a flat road with no wind at 15 mph^[2] = 704 kcal
• D_pg = my mileage if I could somehow consume a gallon of gasoline = (E_g/p) × 15 = 660.5 mpg
• D_pm = my mileage on a gallon of 2% milk = (E_m/p) × 15 = 41 mpg
• D_pr = my mileage on a gallon of cooked white rice = (E_r/p) × 15 = 90.7 mpg
• C_fg = cost to drive the Forester one mile = P_g/D_fg = $0.17
• C_pg = cost to ride my bike one mile if I could somehow consume gasoline = P_g/D_pg< $0.01 (greater than half a significant digit [$0.005]
• C_pm = cost to ride my bike one mile powered by milk = P_m/D_pm = $0.09
• C_pr = cost to ride my bike one mile powered by rice = P_r/D_pr< $0.01 (less than half a significant digit [$0.005]

Notes

^[1] Assumes 2 cups of cooked rice = 1 cup dry rice weighing 8oz
^[2] A pretty leisurely speed for me under those conditions, so I might actually burn fewer calories than this, i.e. get better “gas mileage”