Tesla Reveals Update to Correct Range Discrepancies in “The D”

2014 Tesla Model S (Credit: Tesla Motors)

Apparently Tesla has had a few questions regarding the actual range of the new D variants of the Model S, so it decided to take to its blog to educate customers and to reveal a new update.

The most important bit of news is the new “torque sleep” update for the all D versions of the Model S. Much like many all-wheel drive systems, the dual-motor system in the D versions of the Model S creates a bit of an issue in terms of range, as it is constantly delivering power to all four wheels. In more modern AWD systems, there are measures in place to decouple two of the four wheels when cruising in order to conserve fuel, and it appears as if the new “torque sleep” update for the Model S will act in a similar manner.

This new update will sense when the Model S is cruising at a steady speed and allow one motor to spin freely in the “torque sleep” mode. Once the driver gooses the skinny pedal a bit, the Model S’ second motor awakens and is ready to go full tilt without the driver even noticing the difference. According to Tesla, this should increase the range of the dual-motor Model S by about 10 percent.

According to Tesla, this update should put the P85D variant at 253 miles of total EPA-certified range and put the 85D at 270 miles, but the automaker is still awaiting final certification. For those of you keeping score, that’s a 22-mile decrease from the range that Tesla initially estimated for the P85D and 25 miles less than the original estimates for the 85D.

2015 Tesla Model S driving range graph (Credit: © Tesla)

Tesla does clarify the discrepancies by mentioning that it uses a “cruising range” system to compare its cars at a set speed of 65 mph. In the “cruising range” table that Tesla included with its blog post it shows the 85D traveling 295 miles and the P85D traveling 285 miles at 65 mph with the “torque sleep” software installed. Bumping the speed up to 75 mph drops the range of the 85D and P85D to 249 and 240 miles, respectively. This somewhat explains the issue of reduced range that some buyers are experiencing, as it shows range varies greatly depending on speed.

The blog post also clarifies issues with tires and wheels. In the post it mentions that all of its ratings are measured using the standard, 19-inch wheels, and the optional, 21-inch wheels drop the range by approximately 3 percent. Additionally, Tesla claims that the range may fall as much as 5 percent when you are driving on tires with fewer than 1,000 miles on them.

So there you have it, Tesla speak for “sorry for not being up front, but here’s an update to fix our mix up and a brief education on why we’re still right.” I love Tesla and I am still obsessed with the Model S P85D, but sometimes I question the way it keeps things, like the “torque sleep” software, a secret until an issue blows up in its face.