Fuel Efficiency

In the early 1900s, vehicular propulsion was a free-for-all, with gasoline-, electric- and steam-powered cars all vying for popularity. Are we returning to the good ol' days of the automobile?

By Kristen Hall-Geisler

If air is already 78 percent nitrogen, is there really any benefit to paying extra for nitrogen tire inflation? And how can nitrogen-inflated tires save fuel, anyway?

By Kristen Hall-Geisler

Some drivers are drawn to hypermiling because of environmental concerns, while others simply seem to share a passion for fiscal thriftiness. But are there really any safe hypermiling techniques?

By Cherise Threewitt

In general, hypermiling is a dangerous practice. In fact, some of the most effective hypermiling strategies work only because the driver intentionally sacrifices control of the vehicle.

By Cherise Threewitt

Some of these eco-mods appear to be logical, while others seem a bit like wishful thinking. Can the right eco-mod for your car save you money at the pump?

By Cherise Threewitt

As they say, "Your mileage may vary." But if you're new-car shopping, you probably want a reliable fuel economy number. Where do you go? Who can you trust?

By Kristen Hall-Geisler

There are two ways to measure your car's fuel economy: miles per gallon (mpg) and gallons per 100 miles (g/100m). Do you know how to calculate both of these figures?

By Kristen Hall-Geisler

Watching a field of Formula E race cars circle a racetrack is going to require some adjustment on the part of the spectators. Why? Because they're quiet. Chirping-crickets quiet.

By Kristen Hall-Geisler

The U.S. Navy says it could make about 100,000 gallons (378,541 liters) of JP-5 jet fuel each day using ocean water. But how long will it be before the Navy's plan is plausible?

By Cherise Threewitt

Will these hollow strands of laser-cut nickel revolutionize car manufacturing? And would you really want a car body that's just 0.01 percent solid? Maybe -- it's pretty resilient stuff.

By Kristen Hall-Geisler

Specially engineered Flexible Fuel Vehicles (FFVs) can tolerate an E85 mixture of gasoline and ethanol. But will ordinary cars and trucks be able to stand up to the new blend?

By Cherise Threewitt

For a while, many of us imagined the possibilities: streets full of zero-emission electric vehicles (EVs). But the EV concept has suffered from a certain fragility, and some companies have shifted strategies. Let's talk about a few of them.

By William Harris

What if we could derive energy from crops without killing them or generate power using plants and land not needed for food, all through the power of microbes? Meet the newest, greenest "power plant."

Got your eye on a hydrogen-powered vehicle? The energy of the future comes with some baggage, including an uncanny ability to migrate through metals. Here's what you need to know.

By John Perritano

A flex engine sounds like some sort of futuristic motor, but you'd be surprised how long this technology's been around. Is it greener or more efficient than a gas-guzzling engine? Flex your brain muscle and find out.

By Nathan Chandler

Used mainly in the U.S. as pancake syrup, sweet sorghum is exploding in popularity thanks to its other uses as a biofuel and animal feed. How can one plant do so much?

By Becky Striepe

Improving mileage is only one part of dealing with rising fuel costs. Some cars can accept gas blended with ethanol. But how does the vehicle adjust to the switch?

By Melanie Radzicki McManus

Personal rapid transit systems offer a public transportation option that's a bit more comfortable than the average subway or bus. In what ways is a pod car like your own car?

By Clint Pumphrey

Some people believe that algae could very well be the answer to some of our energy problems. But how will we grow enough of it to accommodate all of our needs?

By John Kelly

Do solar powered cars cause pollution? Keep reading to learn about solar powered cars and if they cause pollution.

By Josh Clark

In the future, all of us will own flying cars. Oh, wait -- that's "The Jetsons." Our views of future transportation are a little more realistic, but cars will increasingly use electric power, reducing our dependence on fossil fuels. Right?

By Meghan E. Smith

Gasoline, everyone knows, is a polluting, volatile source for fuel. Still, the vast majority of vehicles around the world depend on it.

By David DeFranza, Planet Green

Flex Fuel? Ethanol? E85? Been wondering what exactly all of this means? Keep reading to learn about new advances in alternative fuels.

By David Goodspeed

While fuel prices may be dropping at a faster rate than the stock market, drivers are still spending huge portions of their budgets on filling the tank.

By David Goodspeed

Doomsday scenarios about when the globe will run out of fossil fuels have been flowing since the 1950s, when Shell geologist M. King Hubbert created a mathematical model showing what would happen to United States domestic oil production in the coming years.

By Eric Baxter