“AM/FM broadcast radio remains the most dependable, cost-free, and accessible communication mechanism for public officials to communicate with the public during times of emergency,” he said in the letter. “As a result, any phase-out of broadcast AM radio could pose a significant communication problem during emergencies.”
Seven automakers say they do not offer broadcast AM radio. Tesla, for example, said the electric drivetrain design is the source of “significant interference to AM radio transmissions.”
That’s because the technology behind the battery-powered motor requires an electromagnetic field, said Jan Becker, founder and CEO of Apex.AI, which designs mobility software. The inverter in the system switches the current from one set of coils to another, changing the electromagnetic field constantly, which turns the motor.
AM radio uses the same process to modulate the amplitude of radio waves.
“You now have two completely separate systems — one is the battery EV motor system; the other one is the radio and the receiver system — that use the exact same physical principle,” Becker said.
Combustion engines also create interference but on a significantly smaller scale. Automakers have added parts to both powertrains to suppress the interference, forcing them to compromise on the efficiency of the motor system. For battery-electric motors, the interference is stronger and requires more suppression. That suppression reduces the motor system’s efficiency by a fraction of a percent, said Becker, but “still, it’s a design compromise.”
General Motors and Mercedes-Benz did not respond to Markey’s inquiry and instead referenced a response from an industry trade group, the Alliance for Automotive Innovation, which implored the government to continue to modernize its emergency alert system.
Anna Yu, a GM spokesperson, told Automotive News that the automaker “offers AM radio on all products” and the company is “evaluating AM radio on future vehicles and not providing any further details at this time.”
Stellantis said in its response letter that it has “not announced the elimination of AM or FM radio from our vehicles sold in the United States” and “continues to offer AM and FM radio as a standard feature in all vehicles.”
Volkswagen said the company has “explored a variety of solutions to reduce interference, but unfortunately none of them work well or are practical” and “our consumers have so far not requested AM radios be installed in our EVs.”