Fuel Efficiency

Eco-activists often indict air travel as a carbon-spewing threat to the global climate. Worldwide, commercial jets pour an estimated 700 million tons of carbon dioxide into the atmosphere each year, leading to headlines like this one in The New York Times not long ago: “Your Biggest Carbon...

Chrysler bought emissions credits from Tesla, Toyota, and Honda, a new report says.

It was the first hybrid car to be sold in the U.S., beating the now-legendary Toyota Prius by a few months. It was a tiny two-seater with a three-cylinder engine, spats over the rear wheel openings to reduce aerodynamic drag, and a host of highly advanced technologies for its time. It was the 2000...

Mild-hybrid systems could proliferate as carmakers work to improve fuel economy, supplier Delphi says.

A Chinese environmental group is suing Volkswagen over its "defeat device" software.

Volkswagen says a small group of employees were responsible for the "defeat device" software.

Volkswagen says a previously-reported issue with fuel-economy figures is less significant than originally thought.

Volkswagen prices continue to slip as the diesel scandal continues.

A Volkswagen official e-mailed European regulators to argue for less-strict emissions rules.

AAA bemoans the replacement of spare tires as a weight-saving measure.

Which 2016 pickup truck is the most fuel efficient?

When a Toyota Prius drive event comes with a handling course, you know that things have changed. And in some ways, the all-new 2016 Toyota Prius hybrid is a very different car from the three generations of Prius that preceded it. Perhaps the main difference is simply that it drives, handles, and...

Saudi Arabia's proposal for upcoming climate-change talks is as much about preserving its economy as reducing carbon emissions.

Leaked patent images purportedly show BMW's ultra-efficient plug-in hybrid research vehicle.

The EPA is testing all new diesel cars in real-world conditions.

While we don't yet know the model name, we do know Hyundai is expected to launch its first dedicated hybrid vehicle at the Detroit Auto Show in January. That car--codenamed 'AE' for now--will go on sale within a year of the fourth-generation Toyota Prius, the car that has defined hybrid efficiency...

The 2016 Chevrolet Colorado and GMC Canyon diesels are officially the most fuel-efficient trucks on sale.

Another day, another Volkswagen emission scandal? It's beginning to seem like it. The latest news is that VW Group in Germany has found "irregularities" in carbon-dioxide emission levels in roughly 800,000 vehicles, mostly diesels, producing fuel-economy figures that were too high. That discovery...

U.S. vehicle-miles traveled continues to climb, but gasoline use stays fairly consistent.

A startup plans to adapt KERS technology for heavy-duty trucks.