EPA Chief Wants to Eliminate Common New Car Feature: “Everyone Hates It”

Get in almost any new non-EV these days, and chances are it has engine stop-start, a fuel-saving feature that turns off the engine when the vehicle is stopped for any length of time at a stoplight or in traffic.

Some of these systems are good, with “good” meaning they transparently put the engine to sleep when your foot is on the brake and your vehicle is stopped, and wake it quickly and smoothly when you move your foot to the gas pedal to accelerate away. Many aren’t good, with inconsistent behavior, jerky engine shutdowns and restarts. Apparently EPA administrator Lee Zeldin, serving President Trump’s administration, doesn’t find much good in the feature.

On the social media platform X, Zeldin more or less hate-posted about engine stop-start, claiming “everyone hates it,” after noting the EPA he runs formerly “approved it.” “It” is the extra credit the EPA gives automakers for including the feature, which must default to “on” so that it’s included as part of the vehicle’s fuel-economy test cycle data. Doing so provides an “off-cycle credit” for shutting down the engine when stopped, which is then is factored into the fuel-economy calculation.

This matters on the EPA’s test procedure for the city driving cycle, where there are five “stops” over fewer than four miles of simulated driving, along with some idling. (There also is a highway portion, and a “combined” value that represents mixed driving and factors in the city and highway figures.) Stop-start can save fuel during those stops and idle periods, which is how automakers are incentivized to include the feature. The EPA notes that including engine stop-start can increase fuel economy by 4 or 5 percent, with a particular benefit in prolonged stoppages like long traffic lights or dense traffic.

Of course, some drivers don’t love their engines cutting out when the vehicle is stopped, which can sometimes dull air conditioning output and the like, so most automakers include an “off” button for the feature, which is typically represented by an icon incorporating the letter “A” surrounded by a circular arrow above the word “OFF,” as seen in Zeldin’s X post.T

As mentioned, to earn the fuel economy calculation benefit, an automaker must set the feature to default “on” every key cycle, so those that can’t stand it have to press that button every time they get in the car. Zeldin’s commutes, it seems, all start with this blood-pressure-raising action. As Zeldin puts it, the feature amounts to little more than a “climate participation trophy,” although there is a tangible fuel economy—and thus cost—benefit to the consumer that goes beyond air quality.

As for Zeldin’s claim the EPA is “fixing it,” it’s absent any additional detail, so we’re left guessing but assume he intends to get the EPA to drop the fuel economy test procedure credit that incentivizes the inclusion of stop-start. It isn’t clear how long such a move would take, since most EPA rule changes must undergo a long period of public comment, followed by a formal rollout with plenty of heads-up for automakers to adjust. Same goes if the EPA were to, however improbably, attempt to make a rule against engine stop-start; it’d require time, public comment, weigh-in from automakers, and more.

Automakers might not shine to being told to abandon a technology they’ve been pushed to develop for years and worked into their current powertrains, and many have even moved on to 48-volt mild-hybrid systems that allow for even more generous engine-off periods (so that even as you’re slowing to a stop, the engine can cut out) and smoother shutdowns and restarts, and even adding little torque boosts at low speeds, expanding the fuel economy and performance benefits whether a separate testing credit is issued or not.

We should also point out that hybrids essentially incorporate stop-start as part of their operation, but their more powerful electric motors make the stop-start events seamless, and all-electric vehicles skip all that stopping and starting altogether because, well, you know.

This to-do about automatic engine stop-start tracks with the administration’s broader lack of support for technologies, tax incentives, or other developments for alternative fuels or EVs. Trump and Republicans generally have said they want to eliminate the federal EV tax credit as part of an upcoming tax bill, while neutering clean energy more broadly—something that would impact Republican-leaning states where wind and solar energy is booming more than Democrat-led ones—and promoting fossil fuels.