100 mpg car

Steve Lapp, a professor from Ontario, says the moment has nearly arrived. "I've actually gotten over 100 mpg on some trips in my 2001 Toyota Prius," he says. The secret? He mounted solar panels on the car's roof to keep the batteries charged when the sun is shining. If Lapp, a backyard big thinker, can get triple-digit mileage occasionally, why can't the world's car manufacturers hit the mark on every drive?

Automotive X prize will soon announce a challenge to design 100mpg car that can be produced in large scale.

Some interesting bites from a very long but very interesting article in Popular Mechanics:

• Body Use of carbon fiber instead of aluminum or steel, because of its superior strength to weight ratio can bring down the weight of the vehicle significantly.
  
• Aerodynamics "We're noticing in the wind tunnel that what you do on the bottom of the car can be more profound than the roof shape. The rear of the car needs to be either long and attenuated or abruptly cut off. A car's wake can have a detrimental effect on the mileage by creating a partial vacuum behind the car, tugging it backward." says Stewart Reed, who chairs the Transportation Design Department at the Art Center College of Design in Pasadena, Calif.
• Tires Tire manufacturers already use silica in the tread compound to help lower rolling resistance. David Van Emburg, Michelin North America's product marketing director, says we could soon see exotic tires with 20 percent lower rolling resistance than today's models.

Ongoing efforts All electric 100 mpg car from Tesla Motors (Jon Mittelhauser has a blog on why you should get yourself a Tesla). The Aptera Concept Car from Steve Fambro of Accelerated Composites have a 330 mpg, 2 passenger car that can cost under $20K (link : pdf file). Popular Mechanics has a design to achieve 100 mpg without too much extra sweat using existing technology.