Whether it's a Hummer that runs on vegetable oil or a hydrogen-powered car capable of breakneck speeds, mechanics are increasingly looking at ways of developing eco-friendly cars that retain the macho appeal of gas-guzzlers, experts say.
For the overwhelming majority of cars and trucks on display at the SEMA car accessories show in Las Vegas this week, fuel consumption and environmental considerations are issues for other vehicles to worry about.
Yet amidst this big, brash celebration of politically incorrect autos, a few unlikely eco-warriors could be found, such as the Ford pick-up modified by Galpin Auto Sports.
The truck's experimental engine runs on bio-diesel and hydrogen, emitting only water vapors. "We're trying to do the right thing for the environment," Galpin president Beau Boeckman told AFP.
"The whole point of what we do is: you don't have to give up performance to be environmental. It shouldn't be a sacrifice, it should work together."
Other mechanics have sought to soup up the hybrid Toyota Prius, the most common "green" car on the market.
West Coast Customs (WCC), which routinely modifies cars at the behest of sports stars and celebrities, displayed a Prius that had been given a luxury and performance make-over.
"The green car is starting to make a big effect on the car world, which takes a big effect in our aftermarket world," said Ryan Friedlinghaus, chief of WCC. "People look at the Prius, the younger generation looks at it and says, 'I wouldn't drive that'. Now we made our Prius and the kids start looking at it.
WCC's modifications improved the Prius' aerodynamics and lightened the car by 100 pounds (45 kilos), Friedlinghaus said.
Another Toyoto Prius had been given an even more radical facelift, helping it achieve a record top speed of 210 kilometers (130 miles) per hour in tests.
"People are surprised to see that this car can run that fast," said Toyota's Thomas Kafka.
The trade show also saw another prototype from Toyota, a beefed up Highlander Hybrid boasting a more powerful engine.
"We want to show to industry insiders that you can do the same thing with a hybrid as with a conventional vehicle," said Toyota's Mark Amstock.
Toyota's example has been taken a stage further by Tom Holm, on non-profit organisation EcoTrek, which promotes education and research into expanded uses of viable renewable energy.
EcoTrek chose the bete-noire of environmentalists, the Hummer, and turned it into a green machine, featuring an engine run on vegetable oil and details such as fake leather upholstery and running boards made from recyclable aluminum.
Holm believes the modified Hummer should appeal to consumers looking for a people carrier that is environmentally friendly.
"You can have an amazing vehicle that adds ecological conscience," Holm told AFP. "You can't take a soccer team to the game with a Prius. You can't tow a boat with a Prius, you can't do everything. Sometimes you need a pick up truck.
"We try to be practical, purposeful and powerful with our vehicles."
Rick Darling, who has been involved with Ford's "999" car, which is run on hydrogen and can clock 320 kilometers per hour, said the company wanted to show that a "fuel cell car could be fun."
"I think people are getting more environmentally conscious," he said. "And you can have fun with a car that's environmentally responsible."
Darling doubts that environmental concerns are a threat to America's love affair with the automobile. "I don't think you're going to ever take Americans' cars away," he said. "It's in our culture."