1% total fuel efficiency of moving a person in a car

I got an email asking me to explain how 1% of the energy in gasoline goes to moving a person in the car. I saw this calculation in The Zero Carbon Car book but it's also in Amory Lovin's book/report, Winning The Oil Endgame:



It's based on the weight of the car and the weight of the passenger. In Rod's case, since there are more people in the car (and diesel engines are more efficient than gasoline), the total efficiency of moving Rod and his passengers is a bit higher than 3%.