Fringe engines

Natural gas and fuel cell vehicles are not growing as quickly as EVs, for good reasons

Battery-fired and plug-in hybrids aren't the only new game on the road. Other new engines are on their way. Some are young, even by today's technology standards, and their number is already dwarfed by the rise of electric vehicles. Yet they will only add to the array of non-petroleum transport options, biting at oil's domination of the segment. Among the alternative technologies listed by the US Department of Energy are hydrogen fuel cells, compressed or liquefied natural gas, and liquid petroleum gas (LPG). Hydrogen fuel cell cars promise to run as cleanly as electric vehicles (EVs). Emissions consist only of water vapour, which is generated by the reaction of hydrogen with the fuel cell ca