Tesla Motors suffered a huge setback on October 20, Tuesday when Consumer Reports downgraded its Model S electric car and pulled its recommendation, due to low reliability survey scores. CEO Elon Musk responded on Twitter after the electric vehicle's (EV) stocks plummeted over 10 percent Tuesday, tweeting that the low dependability ratings were based on early production runs.
In August Consumer Reports magazine gave the Tesla Model S P85D a perfect 100 score. It had to adjust its own ratings system after the e-car technically racked up 103 points.
However, the Model S earned a below-average reliability score from the consumer magazine's 2015 survey, causing Tesla's stock to dive. Last year its score was average.
Musk tweeted his response on Thursday. He explained that Consumer Reports' survey included issues of Tesla's early production cars that had been repaired, and pointed out that 97 percent of Tesla car owners reported that they will likely buy their next vehicle from the automaker, according to Mashable.
Last year Tesla's reliability scores were higher than this year's. Conventional wisdom says that the converse would be true if the latest production runs had the least reliability issues.
In addition, the EV maker loads software updates directly to its electric cars, eliminating the need for dealer servicing. It is possible some customers did not update their onboard software.
However, several of the complaints were about hardware problems. They included the charging equipment, drive train, and computerized central console, according to Fortune.
Tesla's stocks have mostly recovered from their Tuesday free-fall. While the EV company has earned sky-high marks from Consumer Reports for performance and customer service, reliability is another critical factor in its complex evaluation system.