The system drops a vehicle's fuel consumption anywhere between 4%-26%, depending on the driving mode and traffic. It is, however, controversial among drivers, as it has to be turned off every time.https://www.notebookcheck.net/US-government-to-nix-start-stop-emissions-mandate-that-turns-engines-off-at-traffic-lights.1017231.0.html
A typical overblown complaint solely levied by lead brained boomers that the current administration is full of and serves. Nobody under the age of 50 has ever complained about this.