Consumer Reports' enthusiasm for Tesla electric cars has fluctuated, but owners' enthusiasm has apparently remained steady.

The magazine that once declared the Tesla Model S to be the best car it ever tested, but more recently it has raised concerns over reliability, and criticized the automaker's Autopilot driver-assist system.

Nonetheless, Tesla once again topped Consumer Reports' annual customer satisfaction rankings this year.

DON'T MISS: Tesla falls even further as Consumer Reports ranks reliability

The rankings are based on a survey of owners of cars one to three years old, with scores for each model considered in a brand's overall ranking.

The customer satisfaction index for individual models is determined by the percentage of owners who responded "definitely yes" to the question of whether they would buy their cars again.

In the case of Tesla, 91 percent of owners said they would buy their cars again.

2017 Tesla Model S

2017 Tesla Model S

For comparison, only 84 percent of owners of the next-highest ranked brand, Porsche, said they would buy their cars again.

The survey covered model years 2014 through 2017, encompassing over 300,000 vehicles.

ALSO SEE: Tesla Autopilot 8.0 better, still needs improvement, says Consumer Reports

Owner satisfaction scores are separate from Consumer Reports' own road-test and reliability rankings, and in fact some cars that score poorly in those tests but are still well liked by their owners.

This was the first year Tesla appeared in Consumer Reports' reliability rankings as a brand, but its debut was not auspicious.

2016 Tesla Model X

2016 Tesla Model X

To qualify for these rankings, an automaker must have two models on sale for a long enough period of time for the magazine to gather sufficient data, and large-scale deliveries of the Model X made that possible for Tesla in 2016.

But Consumer Reports found issues with the Model X and so, despite noted improvement in Model S predicted reliability, Tesla ranked 25th out of 29 brands.

MORE: Consumer Reports' view of Tesla Model X: 'fast but flawed'

In its own review, the magazine called the Model X "fast but flawed," praising the electric crossover's performance, but criticizing the interior, ride quality, and 17-inch touchscreen display.

Consumer Reports has also criticized Tesla's Autopilot system, saying Tesla must add more safeguards, and has called the name "Autopilot" misleading, because it implies that the system allows fully-autonomous driving (it does not).


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