Approximately 28% of all the energy consumed in the United States consumed used for transportation (see Figure 1), with the majority of this being derived from petroleum products. Of this, gasoline is the predominant transportation fuel, accounting for 56% of total US transportation energy use in 2014. Diesel fuel, used primarily by heavy duty trucks, accounts for 22%, and jet fuel at 11% are the next largest types of transportatoin fuel. (See Figure 2 and OWOE: What are the different forms of transportation fuel?
). About three-quarters of the 7 billion barrels of petroleum products that were consumed in the US in 2014 were for transportation.
Current trends in the industry, including improvements in gasoline engine efficiency, an increase in the number of hybrid and all-electric vehicles, the new fuel cell vehicles, and development of biofuel alternatives to petroleum, have the potential to eliminate the need for importing oil in the relatively near future. Looking beyond imported oil, there are some who believe that an oil-free transportation industry in the US is possible within 2 decades. However, it is difficult to see how petroleum-based fuel can be completely replaced, in particular for transportation uses such as jet fuel which require very high energy content per pound of fuel.