In 2000 Jonathan Goodwin, a self-described gearhead", bought his first Hummer, an old H1, in Denver, Colorado. "The thing did eight miles to the gallon and nought to 60 in about two days," he recalls. On his drive home to Wichita, Kansas, it broke down three times. The engine died. Rather than fix the engine, he replaced it with a new Duramax diesel and doubled the fuel economy to 20 miles per US gallon (equivalent to 24 miles per Imperial gallon), tripled the horsepower to 600 and quadrupled the torque to 1,200ft lbs. Driven by his quest for more power and less consumption he had inadvertently stumbled across a solution for America's SUV-loving masses. The byproduct of the system he installed is lower emissions - a greener output for these thirsty beasts. "Now we can have our cake and eat it," he says. "It's difficult for these huge companies. The technology is there to make cars that have vastly improved consumption figures already, but they're driven by the need to sell all the cars they currently make," Goodwin says. "If they announced they were bringing out a 100mpg car then no-one would buy the old line." Goodwin sees three stages to a process of change: converting all autos to diesel which can then run on biofuel, making the step to bio-electric and finally to hydroelectric, meaning cars will run on water.