A man cleans a Tesla Model 3 car during a media preview at the Auto China 2018 motor show in Beijing on April 25. (Jason Lee/Reuters)

Updated with statements from Tesla chief executive Elon Musk and Consumer Reports.

For much of the past year, Tesla’s Model 3 has been the darling of auto reviewers everywhere, with some comparing the mass market sedan to the iPhone and labeling it one of the greatest tech products ever created.

This week, Tesla’s string of good reviews came to a halt when Consumer Reports — a publication devoted to authoritative product testing — handed the Model 3 a crushing review.

“Our testers also found flaws — big flaws — such as long stopping distances in our emergency braking test and difficult-to-use controls,” the publication said.

“These problems keep the Model 3 from earning a Consumer Reports recommendation.”

The negative review arrives amid a blitz of negative Tesla headlines. Those headlines have raised questions about chief executive Elon Musk’s behavior during a recent earnings call and the slow pace of Model 3 production, as well as several investigations into the performance of Tesla vehicles.

The National Highway Traffic Safety Administration launched an investigation last week into a crash involving a Tesla Model S. The vehicle was in autopilot mode when the accident had occurred, the driver reportedly told authorities. If true, then that crash would be the second accident this year that has occurred when a Tesla was operating in the semiautonomous driving mode.

Consumer Reports’s review doesn’t mention any issues with the vehicle’s semiautonomous driving technology, but it does say the Model 3’s stopping distance at 60 mph — approximately 152 feet — is “far worse” than any recent model they’ve tested and “about seven feet longer than the stopping distance of a Ford F-150 full-sized pickup.”

The publication says its results are “21 feet longer than the class average of 131 feet for luxury compact sedans and 25 feet longer than the results for its much larger SUV sibling, the Model X.”

To perform the test, the publication’s testers slam on the vehicle’s brakes when the car is traveling 60 mph and measure the distance the vehicle travels until it comes to a stop. The test is repeated multiple times with multiple cars, the publication claims,  and the brakes are cooled between tests to ensure they don’t overheat.

Asked to respond to Consumer Reports claims, Tesla said the company’s own tests have yielded far better results.

“Tesla’s own testing has found braking distances with an average of 133 feet when conducting the 60-0 mph stops using the 18” Michelin all season tire and as low as 126 feet with all tires currently available,” Tesla said. “Stopping distance results are affected by variables such as road surface, weather conditions, tire temperature, brake conditioning, outside temperature, and past driving behavior that may have affected the brake system.”

“Unlike other vehicles, Tesla is uniquely positioned to address more corner cases over time through over-the-air software updates, and it continually does so to improve factors such as stopping distance,” Tesla added.

In response to Consumer Reports, Musk called the results of the publication’s test “very strange” on Twitter and promised to resolve any braking issues the Model 3 exhibits.

Within hours, Consumer Reports released a statement applauding Musk’s reaction and pledging to re-test the Model 3 once the vehicle’s braking system has been updated.

Consumer Reports was also sharply critical of an element of the Model 3’s cabin that has previously received rave reviews: its controls. Those controls are embedded in the vehicle’s touch-screen, which many reviewers have lauded for its sleek design and convenience. Consumer Reports, meanwhile, argued that the screen makes it more difficult for riders to accomplish “simple tasks,” such as adjusting the air conditioning and the car’s mirrors.

“These types of complex interactions with a touch screen can cause driver distraction because each act forces drivers to take their eyes off the road and a hand off the steering wheel,” Consumer Reports states.

The publication’s review wasn’t all bad, however. Consumer Reports labels the Model 3 an “impressive performance sedan” and notes that the car went from zero to 60 mph in 5.3 seconds and offers drivers handling that is “reminiscent of a Porsche 718 Boxster.”

“In fact,” the publication adds, “our testers found the Model 3 thrilling to drive.”

Correction: An earlier version quoted Consumer Reports’s review of the Tesla Model 3, which compared the handling of the Model 3 to a Porsche 917 Boxter. Consumer Reports now says it had meant the Porsche 718 Boxster. This version has been corrected.

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