Fuel Efficiency

Of the three brands caught up in the Volkswagen diesel emission scandal in the U.S., Porsche was by far the least affected. It had sold only one diesel model, a version of its Cayenne performance SUV fitted with a 3.0-liter turbodiesel developed by its VW Group sibling Audi. Regulators approved...

Electric cars may be all the rage, but for now, all but a tiny fraction of the 250 million vehicles on U.S. roads burn gasoline or diesel fuel. One of the ways that new vehicles are boosting fuel efficiency is the use of what are called "start-stop" systems, which switch off the engine while the...

With the release of proposed new and lower fuel-economy rules expected from the NHTSA by March 30, many eyes have turned to the powerful California Air Resources Board. The state's pioneering role in reducing emissions and cutting air pollution predates even the existence of the U.S. Environmental...

It's been clear that under the Trump administration, the NHTSA and EPA plan to roll back linked fuel-economy rules and emission limits on new vehicles. Now a possible justification that will be used has emerged—and it's not the one many advocates had expected. According to a Bloomberg report...

The Toyota Prius hybrid has been its maker's "halo car" and an example of its most advanced technology for two decades. Launched from an early-1990s project to halve the fuel consumption of a small car, its hybrid-electric powertrain pioneered mass electrification of passenger cars. But the sales...

The last time Ford released a new hybrid or plug-in electric model was for the 2013 model year, and that's a long time ago in electric-car years. Detroit's second-largest automaker continues to work on boosting the fuel-economy ratings of its vehicle lineup, however. The latest example is a new...

The Mercedes-Benz CLA compact sedan made a big splash when it first arrived as a 2014 model, complete with a much-discussed Super Bowl ad spot the previous year. The small, coupe-like sedan was built on the underpinnings of the smallest Mercedes on the market, the A-Class sold in Europe since the...

Nearly a year ago, we published a gas-mileage review on the Hyundai Ioniq Hybrid, the South Korean brand's Toyota Prius challenger. We saw 49.5 miles per gallon over 565 miles of driving. Now, we've tested the Ioniq Hybrid in more extreme conditions, on the cold, wintry roads of Detroit, Michigan...

If the U.S. is serious about reducing carbon emissions from road vehicles—under the current administration, the jury remains out—pickup trucks are key. More than half of the reduction in fuel consumption in pickup trucks projected under corporate average fuel economy rules comes from...

In a recent video posted to YouTube, environmental advocacy group The Sierra Club dialed up production values to call out Ford's lobbying efforts to roll back fuel-economy standards. The video showed a man getting into a modern-day Ford, starting the engine, then noting the shift lever had an array...

U.S. car buyers have increasingly ignored passenger sedans and hatchbacks and replaced them with utility vehicles of various sorts, and that's a trend that shows no sign of abating. One reason is that crossovers and SUVs now get better fuel economy than they did 10 years ago, when owning one...

As nations, automakers, and utilities contemplate how to tackle climate change in real terms, a perfect storm of competition is brewing that will—ideally—produce positive change for the rest of us. Automakers and electric utilities have been incentivized to build electric vehicles and...

The forthcoming diesel-powered 2019 Chevrolet Silverado will, without a doubt, thump with the Heartbeat of America. During the new truck's launch at the 2018 North American International Auto Show in Detroit, GM product chief Mark Reuss hinted at a future announcement regarding the next-generation...

It looks like GM's investment arm, GM Ventures, has borne some real-world, fuel-saving fruit. Sophisticated engine-control algorithms under the hood of the 2019 Chevrolet Silverado full-size pickup truck, which make the truck's V-8 engines more efficient, came from work done by a company in which...

One year ago at the Detroit auto show, a company called Achates Power unveiled models of a new kind of internal-combustion engine. With opposed pistons in the middle and crankshafts at either end, it was sufficiently different to startle most visitors who paid attention. That engine came with some...

Pick-ups and SUVs are rapidly taking over the American automotive landscape, but there's at least one measure in which it benefits an automaker to sell fewer of those vehicles. In the Environmental Protection Agency's latest "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel...

It's been hanging out there in limbo for more than six months: the answer to the question of what happens to gas-mileage rules under Trump. Given the daily political turmoil emanating from Washington, D.C., the fate of corporate average fuel economy rules may have gotten lost in the noise. But for...

The dominant news at the 2018 North American International Auto Show in Detroit was about pickup trucks. Ironically, the Detroit automaker with the fewest electrified models on sale was the only one to bring hybridization to a new truck, in the form of its brand-new 2019 Ram 1500. Fiat Chrysler...

The three most significant debuts at the 2018 Detroit auto show were pickup trucks, one from each of the Detroit Three automakers. The 2019 Chevrolet Silverado full-size pickup led on Saturday night, followed on Sunday by the 2019 Ford Ranger, a mid-size pickup that rivals the Chevy Colorado on...

The highest-volume vehicle GM sells in North America is a full-size pickup truck—one that likely also contributes outsize profits from each of its hundreds of thousands of units. So the launch of the 2019 Chevrolet Silverado Saturday night before the Detroit auto show was a big deal for the...