Internal combustion engine powered by ignition of fuel in compressed air. Offers greater flexibility and performance than steam engines, as well as substantially lower operating and maintenance costs.
Turbocharged diesel engine. Improves the fuel economy by recovering waste heat from the exhaust, increasing the excess air factor, and increasing engine output.
The most advanced diesel engine. Added intercooler further increases engine performance by cooling down the air-mass and thus allowing more air-mass per volume.
Engine that converts electricity to motive power. Requires energy source, but has much higher efficiency, and generates almost no air and noise pollution compared to a diesel one.
The most advanced electric engine. The outstanding efficiency of this engine allows building high-speed and super powerful vehicles which will be very costly and impractical otherwise.