Fuel Efficient Cars: How Far Are We From 100 Miles Per Gallon?

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?

While we dream of a what a futuristic world would be like where cars run on water and there will be no power grids, etc., in today's world it is within our grasp to reach 100 mpg with existing technology. Automotive X prize will soon announce a challenge to design a 100mpg car that can be produced in large scale.

Popular Mechanics published a nice article on what such a car will need in its design. In short, mileage can be boosted by an aerodynamic shape, reducing weight, and decreasing friction losses. Here are some interesting bites from that very long article:

• 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, California.
• 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.

Tesla Motors has an all electric 100 mpg car. Both Tesla and the cars based on solar technology remain very expensive.The Aptera Concept Car from Steve Fambro of Accelerated Compositeshave a 330 mpg, two passenger car that can be built for under twenty thousand US Dollars (link: pdf file). Popular Mechanics highlights a possible design to achieve 100 mpg using existing technology.

Unshackled from the constraints of today's technology, one is free to wonder about the future. Such a future lies with flex fuels and the ultimate among them - electricity! The ultimate energy solutions in large-scale will come from wind, solar and hydrogen technologies. On a small scale the power in very compact settings will be delivered by small but high capacity batteries. There is already one simple technology we cherish that hardly use any power: the transistor and semiconductor based devices. Very soon others will be modeled after this. Or so I dream.