91��Ƶ

Ford Motor Co. revealed its emission testing could be flawed and took pains to soothe anxiety among investors in an industry wracked by years of pollution scandals.

California environmental regulators are aggressively moving forward with plans to require significant reductions in nitrogen oxides and particulate matter emissions for heavy trucks, improvements in “real time” on-board diagnostics, and lengthening the “useful life,” durability and warranty periods for heavy trucks.

Volvo Group said it could not yet determine the impact of a faulty component on its North American trucks as it was still evaluating the scope of the problem.

Volvo, the world’s second-largest truckmaker, has uncovered a faulty component in the emissions-control setup of vehicles widely sold in Europe and the U.S., the manufacturer’s biggest markets.

California is considering a formal, public counter-proposal to President Donald Trump’s proposed rollback of fuel and pollution requirements for cars and trucks.

To test how Americans feel about its plan for rolling back car and truck pollution standards, the Trump administration will hold an initial public hearing Sept. 24 in Fresno, Calif., a place where it might reasonably expect a friendly response.

Fleets continue to encounter challenges dealing with aftertreatment technologies that are now being refined after major changes in years past. From a maintenance perspective, aftertreatment systems are improving.

DENVER — The Trump administration is rolling back some U.S. regulations on climate-changing methane pollution, calling them expensive and burdensome, but Colorado says its rules are working — and they have industry support.

The Trump administration’s plan to ease vehicle-emission mandates lifts some burdens for automakers but also would strip away options that have made it easier for them to comply and have encouraged the development of electric cars.