a carrying capacity of . After World War I, several advances were made: electric starters, and 4, 6, and 8 cylinder engines. Diesel engines Although it had been invented in 1897, the diesel engine did not appear in production trucks until Benz introduced it in 1923. The diesel engine was not common in trucks in Europe until the 1930s. In the United States, Autocar introduced diesel engines for heavy applications in the mid-1930s. Demand was high enough that Autocar launched the "DC" model (diesel conventional) in 1939. However, it took much longer for diesel engines to be broadly accepted in the US: gasoline engines were still in use on heavy trucks in the 1970s. Electric Motors Electrically powered trucks predate internal combustion ones and have been continuously available since the mid-19th-century. In the 1920s Autocar Trucks was the first of the major truck manufacturers to offer a range of electric trucks for sale. Electric trucks were successful for urban delivery roles and as specialized work vehicles like forklifts and pushback tugs. The higher energy density of liquid fuels soon led to the decline of electric-powered trucks in favor of, first, gasoline, and then diesel and CNG-fueled engines until battery technology advanced in the 2000s when new chemistries and higher-volume production broadened the range of applicability of electric propulsion to trucks in many more roles. Today, manufacturers are electrifying all trucks ahead of national regulatory requirements, with long-range over-the-road trucks being the most challenging. Etymology Truck is used in American English, and is common in Canada, Australia, New Zealand, Pakistan and South Africa, while lorry is the equivalent in British English, and is the usual term in countries like Ireland, Malaysia, Singapore and India. The first known usage of "truck" was in 1611 when it referred to the small strong wheels on ships' cannon carriages, and comes from "Trokhos" (Greek) = "wheel". In its extended usage, it came to refer to carts for carrying heavy loads, a meaning known since 1771. Its expanded application to "motor-powered load carrier" has been in usage since 1930, shortened from "motor truck", which dates back to 1901. "Lorry" has a more uncertain origin, but probably has its roots in the rail transport industry, where the word is known to have been used in 1838 to refer to a type of truck (a goods wagon as in British usage, not a bogie as in the American),