Tesla Model S P85D owners say the car is not making the power stated by Tesla

71 Owners of Tesla Model S P85D got together and wrote this open letter to Tesla.

“We are writing to you as a group of concerned Tesla owners, investors, and perhaps most importantly, supporters,” a group of 71 Tesla owners have contacted Elon Musk through an open letter. “The P85D was marketed as making 691 horsepower. It doesn’t. We believe, based on various testing methods and tools including dynamometer testing and testing with professional performance data loggers that the maximum energy output is 415 [kilowatts], which results in a maximum horsepower of 557 before any drivetrain losses on a fully charged battery. The missing horsepower is quite noticeable at highway passing speeds” where “the P85D is easily outperformed by an Audi RS7.”

Tesla’s chief technical officer JB Straubel commented through the producer’s blog that “there is some confusion about our methodology for specifying ‘equivalent’ horsepower ratings for our all-wheel drive, dual motor vehicles.”

“The shaft horsepower rating of the rear wheel drive single motor Model S is straightforward and roughly 360-470 [horsepower] depending on the variant (60, 85 or P85),” he stated. “When we launched the all-wheel drive P85D, we took the straightforward and consistent approach of specifying the combined capability of the two electric motors, front + back.”

Source: HybridCars and TeslaMotors