Unbelievably Inefficient Cars

Less than 10% of the fuel energy burned in automobiles is translated into forward motion of the vehicle and even then most of this energy is needed to move the vehicle itself, which typically weighs 20 times more than its passengers.

~ David Suzuki Foundation (1990 age:27) 2002-09

In contrast, a bicycle weighs about 1/8 of the weight of its rider and it can get as low as 1/50.