Consumer Reports has found "big flaws" with Tesla's Model 3 car, the more affordable sedan unveiled by the electric car maker in 2016 as it tries to crack the mass auto market.

The problems "keep the Model 3 from earning a Consumer Reports recommendation," the influential magazine said in its review.

Chief among Consumer Reports' concerns is what it describes as inconsistent braking, including long stopping distances. The magazine tests cars for the distance they require to come to a stop when the driver hits the brakes at 60 miles per hour. The Model 3 required 152 feet, which CR said was "far worse than any contemporary car we've tested."

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By comparison, the average luxury compact sedan stops in 131 feet, the magazine said.

Tesla (TSLA) is already facing questions about whether it can build Model 3s fast enough to meet consumer demand, and assuage mounting concern from investors. The mixed review from Consumer Reports, which also praised the Model 3's handling, acceleration and "record-setting range," contrasts with the magazine's rating for Tesla's Model S, the $75,000 car that received the highest score the magazine has ever handed out.

In an emailed statement, Tesla said its own testing found an average braking distance for the Model 3 of 133 feet, using the 18-inch Michelin all-season tire, noting that it had recorded braking distances as low as 126 feet.

"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," the spokesperson wrote in the email. "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."

Braking test

Consumer Reports said its braking test is meant to assess how a vehicle performs in an emergency. Because the magazine found inconsistent braking performance in the first Model 3 it tested, it ran the same test on a second Model 3.

"We got almost identical results," CR said. "In our tests of both Model 3 samples, the stopping distances were much longer than the stopping distances we recorded on other Teslas and other cars in this class."

Poor driver controls

Consumer Reports also dinged the Model 3 for its controls, which are placed on a central touch screen, similar to a large iPad. The dashboard lacks gauges and buttons, which means that drivers need to use the touch screen to do everything from adjusting mirrors to changing the air-conditioning flow.

The interior and control panel of the Model 3. Reuters

"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 noted.

Not the first negative reviews

Consumer Report's negative review isn't the first to sideswipe the Model 3.

In a March 8 review, Green Car Reports said the build quality of the car "was the worst we have seen on any new car from any maker over the last 10 years." Edmunds.com also found gaps between body panels and a broken framework on the driver's seat. And individual owners have complained about problems ranging from dead batteries to protruding headlights.

On the positive side, Consumer Reports praised the Model 3's "otherwise impressive performance."

"It delivered a blistering 0-to-60-mph time of 5.3 seconds, and its handling was reminiscent of a Porsche 917 Boxster," the magazine noted. "In fact, our testers found the Model 3 thrilling to drive."

In testing, the Model 3 also went 350 miles on a single charge, the farthest Consumer Reports has ever tested, when using Tesla's "regenerative" braking mode, which slows the car and charges the battery as soon as motorists step off the accelerator pedal.