Tesla Model S scores 103 from Consumer Reports on 100-point scale

Consumer Reports, in what at first appears to be a case of grade inflation, has given a new, top-of-the-line version of Tesla Motors’ TSLA, +8.07% Model S sedan a 103-point score — out of a possible 100.

The not-for-profit U.S. consumer guidebook gushed it had to “make changes to its scoring methodology to account for the car’s exceptionally strong performance." With those changes now in place, Tesla’s scale-bending 103 points once again fit within the magazine’s 100-point top rating.

Consumer Reports latest review tested the all-electric Model S sedan’s P85D version, which starts at $105,000 and sports all-wheel drive and a more powerful battery than earlier editions. As tested, the car cost the magazine $127,000.

The P85D “catapults you forward," Jake Fisher, the head of Consumer Reports car testing program.

Fisher, who regularly takes test cars home, said his two sons, aged 7 and 11, encouraged him “to accelerate (the P85D) every time they had a chance. They used it as an amusement park ride." The seven-year-old said “all his blood went to the back of his head," Fisher said.

Two years ago, the magazine awarded the Model S a near-perfect 99-point score, and earlier this year named it the best car overall for a second year in row. The more powerful version is the only car to score 100 in the magazine’s revamped ratings system, topping Mercedes Benz’s S550, which scored 96, Consumer Reports said.

Usually, a car company’s higher-performance models are less energy efficient, Fisher said. So he said he was genuinely surprised when tests showed the more powerful Model S also to be more efficient than its predecessor.

The P85D comes with a 85 kWh battery that can be upgraded to 90 kWh. According to Tesla, it can go 253 miles between charges and hit 60 miles per hour in 3.1 seconds. Consumer Reports couldn’t match that speed, saying its test car clocked zero to 60 mph in 3.5 seconds.

Consumer Reports has been critical of the Model S at times. In May, the magazine said the P85D suffered a broken power door handle even before official testing began. The company fixed the problem quickly, however, and the magazine resumed its tests.