Fuel Efficiency

Passenger SUVs are to blame for growth in CO2 emissions, an upcoming paper finds, while the passenger-car sector has made CO2 reductions.

Until electric trucks arrive, the Ram EcoDiesel is the way to haul heavy loads without guzzling fuel at alarming rates.

Changes to federal emissions and fuel economy standards have lasting (and delayed) effects to major shifts in fleet fuel economy.

Mercedes-Benz E-Class and C-Class diesel models are at the center of a nearly $1 billion fine in Germany.

California is not yet doing enough to clean up its emissions, the EPA says, as it looks to revoke the state's authority in favor of lower emissions standards.

Andrew Wheeler now says that the administration isn't committed to revoking California's emissions authority.

In a plan drawn with the EPA and NHTSA, the Trump administration is aiming to take vehicle emissions authority away from California.

The push for higher-mileage new cars isn't as controversial as the federal government might be making it sound.

The German supplier ZF has developed a 2-speed transmission that could help improve electric-car efficiency and driving range.

The National Highway Traffic Safety Administration has acted to freeze fines for companies that violate federal fleet fuel economy standards.

A wide range of Hyundai and Kia vehicles, starting with the 2020 Sonata, will be soon be getting engines with a next-generation valve system.

Automakers (17 of them) wrote a letter to President Trump asking for California to be included in his single national standard for revamping fuel economy rules.

Michelin has introduced a prototype airless tire that will soon be tested on a Chevrolet Bolt EV fleet in Michigan.

If the federal government revokes California's waiver allowing it the authority to regulate emissions, the state's agency is making clear it will find a way to keep the polluters out.

Tesla has replaced the induction motor at the front of its Model S and Model X with a permanent-magnet motor, as used at the rear axle of the Model 3.

If more power, a 226-mile range, and a $39,405 base price—before considering the full $7,500 federal EV tax credit you can still get—collectively seems like the sweet spot for the Leaf, you probably have GM to thank. Nissan has admitted that it never planned to push the Leaf above a...

Given the daily churn of electric-car announcements, major manufacturing investments, and battery supply-chain news, it could be a little hard to understand one reality-check projection: that even in 2030, a solid majority of vehicles sold could still burn fossil fuel. Last week, LMC Automotive, a...

An EPA report released Wednesday shows that cars are getting better gas mileage in response to rising fuel economy standards. Yet a roaring economy and low gas prices have put Americans on a truck-buying spree, and the EPA is working to undermine those standards. According to its annual automotive...

In just one model year, Kia has more than doubled the rated driving range for the Soul EV. The 2020 Kia Soul EV, which is expected to reach dealerships this spring, will go 243 miles on a charge—four more miles than the Kia Niro EV—according to the EPA, in ratings that were released...

It turns out there's more than one way for automakers to meet fuel-economy targets. One is to develop and sell more fuel-efficient cars and trucks. The other—as demonstrated over the years by quite a few automakers—is to pay fuel economy fines to the U.S. Treasury as a course of doing...