Tesla uses over-the-air software updates to quickly add new features to its electric cars, or to correct problems without the need for customers to bring their cars to service centers.
But one apparent software update rankled more than a few Tesla owners: it limits the number of times Launch Mode can be used with specific battery packs, reducing performance once a limit determined by Tesla is reached.
UPDATE: Two weeks after news of the limit came to light in early January and after feedback from its owners, Tesla announced that it will remove the software limiter in its next software update, due to roll out in roughly three weeks.
Similar to the launch-control systems in many internal-combustion performance cars, Launch Mode is an electronic aid intended to make it easier for drivers to achieve maximum acceleration from a standstill.
The Launch Mode limit was first mentioned on the Tesla Motors Club forum by user Ingineer, who is known to have extensive access to the software in his Model S.
In the same thread, a Model S P90D owner claimed his car had in fact been limited after using the feature.
2015 Tesla Model S P85D in Ludicrous mode jumped at start of drag race [photo: George Parrott]
He said the car previously pulled 1,600 amps and 512 kilowatts (686 horsepower) of power, but at some point became limited to 1,500 amps and 480 kW (643 hp).
A Tesla representative told this owner that because Launch Mode "places an increased stress on the entire powertrain," Tesla does have limits in place for the Model S P90D.
The car's computers "automatically track Launch Mode usage and continually estimate fatigue damage," the Tesla representative said.
"Depending on how Launch Mode is used, the computer may eventually limit the available power during Launch Mode to protect the powertrain," the representative said, calling such limits a "common strategy" among high-performance cars.
The owner was told that upgrading to the Model S P100D with Ludicrous Mode would solve the problem, as that version does not have the limiter.
Responding to owner outcry over the limit, a Tesla Motors representative posted the following note on the Tesla Motors Club discussion thread:
Tesla Model S drag-races 2015 Dodge Challenger Palm Beach Intl Raceway, Hellcat, Jan 2014 [YouTube]
Based on your input, we have decided to remove all software performance reductions tied to frequent max power usage. These changes will roll out with our next software update (in about three weeks).
We had put these reductions in place to proactively protect the powertrain from wear and tear.
Instead, we will monitor the condition of the powertrain and let our customers know if service is needed so that we can take proactive steps, such as by replacing parts if necessary, to maintain the vehicle’s performance.
Tesla had previously added language about "limiting controls" to the performance disclaimer on its website.
"Performance versions of the Model S and Model X continually monitor the condition of various components and may employ limiting controls to optimize the overall driving and ownership experience," it reads.