According to the website FuelEconomy.gov, diesel engines can convert 30 to 35 percent more energy from diesel than internal combustion engines can from gasoline. Also, modern diesel vehicles use improved fuel injection technology that increases power, acceleration and overall efficiency.
Internal Combustion Engine
According to FuelEconomy.gov, internal combustion engines that run on gasoline receive only about 15 percent of the energy put in them. This is because a lot is lost through car idling, and engine and driveline inefficiencies.
Electric vehicles use an electric motor powered by several battery packs. According to FuelEconomy.gov, these motors convert 75 percent of the chemical energy in batteries vs. the 20 percent internal combustion engines convert from gasoline.
Hybrid-electric vehicles (HEVs) use an internal combustion engine and an electric motor. The electric motor serves as a backup power source, which reduces the amount of energy lost from the combustion engine, making the vehicle much more energy efficient.
Fuel cell vehicles (FCVs) use electric motors to power a car but rely on a different battery technology. FCVs use polymer electrolyte membrane (PEM) fuel cells. These cells generate electricity chemically by combining hydrogen and oxygen.
Car fuel technology changed drastically in the past century. New diesel, electric, hydrogen fuel cell and hybrid engines are a few examples of technology leading to many new vehicle designs.