and the air is more effective since gases typically mix well in a short period of time. Still, at typical CNG compression pressures, the fuel itself is less energy dense than gasoline or diesel thus the result is a lower energy dense air-fuel mixture. Thus for the same cylinder displacement engine, a non-turbocharged CNG-powered engine is typically less powerful than a similarly sized gasoline or diesel engine. For that reason, turbochargers are popular in European CNG cars. Despite that limitation, the 12 litre Cummins Westport ISX12G engine is an example of a CNG capable engine designed to pull tractor/trailer loads up to showing CNG can be used in most if not all on-road truck applications. The original ISX G engines incorporated a turbocharger to enhance the air-fuel energy density. LNG offers a unique advantage over CNG for more demanding high-horsepower applications by eliminating the need for a turbocharger. Because LNG boils at approximately -160 °C, using a simple heat exchanger, a small amount of LNG can be converted to its gaseous form at extremely high pressure with little or no mechanical energy. A properly designed high-horsepower engine can leverage this high-pressure energy-dense gaseous fuel source to create a higher energy-density air-fuel mixture than can be efficiently created with a CNG-powered engine. Compared to CNG engines, the result is more overall efficiency in high-horsepower engine applications when high-pressure direct injection technology is used. The Westport HDMI2 fuel system is an example of a high-pressure direct injection technology that does not require a turbocharger if teamed with appropriate LNG heat exchanger technology. The Volvo Trucks 13-liter LNG engine is another example of an LNG engine leveraging advanced high-pressure technology. Westport recommends CNG for engines 7 litres or smaller and LNG with direct injection for engines between 20 and 150 litres. For engines between 7 and 20 litres, either option is recommended. See slide 13 from their NGV BRUXELLES – INDUSTRY INNOVATION SESSION presentation High horsepower engines in the oil drilling, mining, locomotive, and marine fields have been or are being developed. Paul Blomerus has written a paper concluding as much as 40 million tonnes per annum of LNG could be required to meet the global needs of the high-horsepower engines by 2025 to 2030. As of the end of the first quarter of 2015, Prometheus Energy Group Inc claims to have delivered over 100 million gallons (380 million litres) of LNG within