Page - 20 - in Our Car as Power Plant

20 So the energy effi ciency to move our car from A to B is between 12 and 24% (3,4,5,6). Most effi ciency calculations stop here, but if we were to continue and take into account the overall purpose of our cars, it becomes even worse. Let’s face it, all we’re trying to do with a car is move our- selves from A to B, a task for which we deploy a 1,000 to 2,000 kg car to transport about 100 kg of human being. So at the end we only have a lousy 1% (between 0.6 and 2.4%) energy effi ciency to move ourselves from A to B in a car. How sad is that! Can we do better? Yes we can! OUR CAR AS POWER PLANT ENERGY EFFICIENCY FROM A TO B BY CAR ENERGY EFFICIENCY WELL TO TANK gasoline 80-85% TANK TO WHEEL engine standby/idle transmission auxiliary use resistance Total tank to wheel 25-40% 80-85% 94-95% 95-98% 85-90% 15-28% WHEEL TO PERSON Weight of car 5-10% CALCULATION Energy effi ciency low = 80% * 15% * 5% = 0.6% CALCULATION Energy effi ciency high = 85% * 28% * 10% = 2.4% FROM A TO B Total 0.6-2.4%