With the Detroit auto show suffering from a lack of groundbreaking model launches by the city's present carmakers, the focus has shifted in the direction of an alternative motoring future founded on innovation and inventions. This year, Michigan State will host a series of competitions that offer a $10m (£6m) reward to the inventors of the world's most fuel-efficient autos.

From high-schoolers modifying a Ford Focus hybrid to operate on biofuel to would-be manufacturers of three-wheeled electric vehicles, the X PRIZE's seven automotive expert judges have winnowed a field of 135 vehicles down to 53, powered by six different fuel sources and coming from 18 states and 10 countries.

The Automotive X Prize contest has dragged on for several years This year the contest began with 28 teams with 36 vehicles. Of those, 24 participated in the shakedown. While that's not a lot of elimination it is an interesting and significant begining.

The competition, sponsored by Progressive Insurance, offers $10 million in prizes to automakers who can create vehicles that get at least 100 miles a gallon.

The contest consisted of technical inspections and on-track safety checks, including zero-to-60 mile per hour acceleration and braking tests, an emergency double lane change avoidance maneuver, and durability requirements.

"These shakedown tests rightly set a very high standard of safety and performance," said Eric Cahill, senior director of the contest. "This was not intended to be simple. If it were, it would have previously been completed. We expect to see additional eliminations during the knockout stage."

The Automotive X Prize is a three-phase competition to build cars that get 100 MPGe or more. The vehicles have to be capable seeing actual production and sold in quantities of 10,000 a year by 2014. They also have to be able to pass all government crash and emissions tests and meet minimum performance standards as determined by Consumer Reports. They also have to pass a 40-mile resilience test drive.

A number of teams have fielded multiple cars, spanning both the competition's chief categories: Mainstream-class cars have to seat at least four people, have four wheels, and at not less than a 200-mile range; and Alternative-class cars have at least two seats, two wheels, and a 100-mile range. (Alternative-class contestants would likely be considered sports cars or motorbikes in production.) In numerous cases, groups with several entries only saw one of their vehicles pass inspection, and the teams will carry on with a particular model in the competition.

It's like the future has finally gotten here," said Gary Starr, founder of the California-based electric carmaker ZAP, whose three-passenger, three-wheeled car is a finalist. "The X Prize validates these vehicles and provides an outlet for small organizations like mine to prepare these vehicles for manufacture."

The rigorous testing begins with thorough inspections and computer modeling to make sure the vehicles can pass tough U.S. crash standards. Ultimately, the testing will move to the track where the vehicles will have to demonstrate themselves on the street.

Connie Bezanson, of the U.S. Department of Energy's Office of Vehicle Technologies, said the need for more efficient cars is paramount.

"About 65 percent of daily U.S. oil consumption comes from autos and 45 percent of the worldwide CO2 production comes from vehicles," she said.

Energy Secretary Steven Chu says the money will give the Automotive X Prize, a $10 million competition to make cars able of 100 mpg or the equivalent, with technical assistance and help enlarge national education and outreach efforts. The funds comes out of the American Recovery and Reinvestment Act, also known as the stimulus package.

"Our unpolluted energy hope is dependent on our ability to design and commercialize new extremely efficient vehicles that are cost-effective for consumers and use considerably less energy," the secretary said. "This funding will support cutting-edge, American innovation that can assist us basically transform personal transportation and address the global climate crisis."

$10 million in awards will be awarded in September 2010 to the teams that prevail a rigorous stage competition for clean, production-capable vehicles that exceed 100 MPG energy equivalent (MPGe). The on-track Competition Phase will be hosted at Michigan International Speedway.

Just 15 cars from 12 teams passed these tests, with most in the so-called "alternative class": two-seat cars with a 100-mile (160-kilometre) range that can accelerate from 0 to 60 miles per hour (about 100 kilometres per hour) in less than 18 seconds. The "mainstream" class, for four-seat cars that have cargo room, a sub-15-second 0-to-60 time and a 200-mile range, proved more challenging. Only one of the nine groups survived the knockout standards to continue on to the finals.

Tough targets

"We thought there might be a few additional contenders than there are at this stage," says Brad Jaeger, director of research and development and driver for the Virginia-based Edison2 team, the lone surviving mainstream class competitor.

Julie Zona, director of team relations for the Automotive X Prize, says that the level of difficulty in the mainstream group is intended to reflect the conventional needs of the market. "We realise that that set of requirements is extremely difficult, so for anyone to hit them is an achievement," says Zona.

The finals, which begin in mid-July, will see teams attempt to meet the full requirements while competing in time trials. The winners of each category will receive a $5 million prize.

Tesla, Nissan, and GM's mass-market offerings may yet prove to be successes, but the X Prize demonstrates that delivering performance to meet drivers' expectations may signify going back to the drawing board when it comes to a car design. Sustainable motoring, while possible, may appear and feel vastly dissimilar from what today's drivers are used to.