New Trump emissions rules cut start-stop feature in cars

President Donald Trump’s administration is rolling back fuel efficiency standards, a move that includes eliminating a credit automakers received for installing start-stop engine technology. The decision, framed by the administration as a benefit to car buyers, signals a broader shift away from regulations aimed at improving vehicle fuel economy.

A Disliked Feature Removed

The core of this change centres on start-stop systems, which automatically shut off a car’s engine when the vehicle is idling – like at a red light – and restart it when the driver presses the accelerator. According to administration officials, this feature has been labelled “universally despised” and an “idiotic requirement.” While not prohibiting automakers from *using* the technology, the administration is removing the incentive that encouraged its adoption.

Historical Context and Recent Adoption

Start-stop technology isn’t new. It first appeared in the 1970s, but gained traction in the 2010s after the Environmental Protection Agency (EPA) began offering automakers credits for its use in 2012. These credits helped manufacturers meet overall fuel economy standards. The Trump administration’s action effectively removes that benefit, potentially slowing the spread of the technology.

President Trump stated that eliminating the credit will result in “a better car, you’re going to get a car that starts easier, a car that works better for a lot less money.” EPA Administrator Lee Zeldin echoed this sentiment, calling the removal of the credit an “added bonus” to the administration’s broader rollback of emissions rules.

Impact on Automakers

Data from the EPA shows varying levels of fuel efficiency among major automakers. In 2023, Toyota achieved an average fuel economy of 27.5 mpg, a 7.8% increase from 2018. Honda followed with 30 mpg, a 1% increase over the same period. BMW achieved 27.6 mpg (a 6% increase), while Ford averaged 23.2 mpg (a 6% increase). Hyundai reached 29.8 mpg (a 4.1% increase), Mercedes-Benz 27.5 mpg (a 17% increase), and General Motors 23 mpg (a 2.6% increase). Volkswagen averaged 27 mpg, a 9.7% increase since 2018.

The administration’s actions are part of a larger effort to revise U.S. Fuel economy rules. Transportation Secretary Sean Duffy stated the administration is working to “make cars more affordable again” and “revitalize American manufacturing.”

What Could Happen Next?

If the incentive for installing start-stop systems is removed, automakers may reduce or halt its implementation, potentially leading to slightly lower overall fuel economy figures. However, manufacturers could still choose to include the technology if they believe it offers other benefits, such as improved vehicle performance or market appeal. It’s also possible that future administrations could reinstate similar incentives, depending on evolving environmental policies and consumer demand. The long-term impact will likely depend on a complex interplay of market forces, technological advancements, and regulatory changes.

Frequently Asked Questions

What is a start-stop system?

A start-stop system automatically shuts off a car’s engine when the vehicle is stopped – like at a traffic light – and restarts it when the driver presses the accelerator.

When did start-stop systems become more common?

Start-stop systems became more common in the 2010s after the EPA began giving automakers extra emission credits for using them in 2012.

Is the Trump administration banning start-stop systems?

No, the Trump administration is not banning start-stop systems. It is removing a credit that automakers received for installing them, which may discourage their use.

As fuel efficiency standards continue to be debated and revised, how might consumer preferences and technological innovation shape the future of automotive technology?