A group of 71 Tesla owners, investors, and supporters have written a lengthy open letter to company CEO Elon Musk in order to voice their concern that the Model S P85D’s official power output is overblown.
Tesla claims the P85D — which is equipped with two electric motors — generates a total of 691 horsepower, a figure that makes it almost as powerful as Dodge’s acclaimed Charger and Challenger Hellcat models. However, the concerned individuals report that the highest figure they’ve been able to obtain by testing the Model S on a dynamometer and with professional performance data loggers is 557 ponies when the battery is fully charged.
“The missing horsepower is quite noticeable at highway passing speeds,” notes the author of the letter. “For example, from 70-90 mph, the P85D should perform like a car with a power to weight ratio of 1 horsepower for every 7 pounds. Instead it performs like a car with 1 horsepower for every 9 pounds. The result of this is that from 70-90 mph the P85D is easily outperformed by an Audi RS 7.”
JB Straubel, the company’s Chief Technical Officer, responded by writing an official blog post that explains a variety of factors make it difficult to compare the power output of an electric vehicle to that of a gasoline-burning model. These factors include the “battery’s temperature, state of charge and age.” Additionally, he pointed out that the weight of the driver and all additional features that add weight to the car can reduce acceleration.
Straubel clarified that Tesla obtained the 691 horsepower figure by simply adding the output of the front-mounted motor to the output of the motor located over the rear axle. In closing, he wrote that “the true measures for any performance EV driver are acceleration times and driving performance of the vehicle.”
Musk has not weighed in on the issue, and the individuals who wrote the letter haven’t responded to Straubel’s explanation. However, the California-based car maker has since removed the 691-horsepower rating from its official website.