A Toyota Prius in 2014. (Kiyoshi Ota/Bloomberg)

In his April 8 op-ed, “The Music Man in the White House,” David Von Drehle incorrectly claimed that this administration is just tweaking “pie-in-the-sky” policies of the prior one. He used his recent experience driving a rented Prius to demonstrate that vehicle fuel-economy standards are an unrealistic goal. However, Mr. Von Drehle’s example showed the opposite of what he thought it did.

In real-world driving, an average new vehicle meeting federal fuel-economy standards for model year 2025 would achieve about 36 miles per gallon, not the 54.5 mpg cited. The 54.5 mpg reflects laboratory test values that far exceed the values posted on consumer fuel economy labels, which better match on-road performance. That means Mr. Von Drehle’s Prius’s 45 mpg was in fact 25 percent higher than the 2025 goal — in 2018.

The vehicle standards in imminent danger of rollback are not bluster; they are achievable, cost-effective requirements. They’re also key to the continuing success of domestic automakers, who must compete in a global industry shaped by increasingly stringent efficiency and emissions standards in all major markets.

What’s now coming down the pike from the Trump administration looks worse, not better.

Therese Langer, Washington

The writer is the transportation program
director for the American Council for an
Energy-Efficient Economy.