Tesla drivers in Florida got an unexpected assist this weekend as they scrambled to evade Hurricane Irma.
Owners of certain Model S sedans and Model X S.U.V.s noticed that the battery capacity of their electric cars had increased, giving them as much as 40 extra miles of range to outrun the deluge. Range anxiety — the fear that an electric vehicle will run out of charge before reaching its destination — can be magnified in emergency situations.
Tesla confirmed that it had remotely enabled a free software upgrade for vehicles in the path of the storm, motivated by one customer who requested the change while making evacuation plans. The free upgrade will expire on Saturday.
Many Tesla owners cheered the temporary enhancement ahead of Irma, which made landfall in Florida on Sunday.
Some, though, said the company was kneecapping vehicle range under normal circumstances in pursuit of profit. Others were concerned that the magnanimous move overshadowed the troubling extent to which Tesla can command customers’ cars.
Most other auto manufacturers “sell vehicles that are incapable of learning and improving and are highly vulnerable to obsolescence,” Adam Jonas, an analyst at Morgan Stanley, wrote in July. But not Tesla, which has become an industry leader in what’s known as over-the-air vehicle upgrades — the ability to make instant fixes without being anywhere near the car.
It’s an efficient method: Wirelessly communicating improvements to a digitally equipped vehicle means that customers don’t have to come in for every small tuneup. But some updates, like a strict speed cap that Tesla rolled back this year, also raise concerns about consumer privacy and control.
Starting in 2016,Tesla produced a run of Model S and X cars equipped with battery packs built to have 75 kilowatt-hours of capacity but constrained by software to have access to only 60 to 70 kilowatt-hours of power. The company began producing cars this way to streamline manufacturing; it could produce the same type of battery but provide different price points, charging customers up to $9,500 for an upgrade to full capacity.
Tesla has since stopped offering the software-limited batteries.
A spokeswoman for Tesla declined to comment and did not specify how many Tesla owners had benefited from the upgrade.
For Chris Forman, a pilot, the $6,000 discount for a 60-kilowatt-hour battery instead of a 75-kilowatt-hour version was enough to persuade him to spend roughly $70,000 on his Model S in November.
“I never thought I was paying for a car that was neutered — I was paying less to get less range,” he said.
Forman, who lives in Broward County, Florida, had flown to St. Louis for work on Friday when he checked his Tesla app and saw that his car, plugged in at home, had reached 242 miles of range and was still charging. He had never seen the vehicle exceed 215 miles.
He said he was impressed with Tesla’s initiative, especially given that the company is in the process this month of ramping up production of its Model 3 mass-market vehicle.
“I was totally blown away. It was super awesome of them to do that,” Forman said of the software upgrade. “Tesla is always thinking outside the box.”
Tesla owners said lines for the company’s roadside Supercharger charging network were uncommon over the weekend. Drivers said they were worried about reliability of the Florida electrical grid during the hurricane.
But at least they could avoid gas stations, which ran out of fuel so quickly and often that police officers had to guard some locations.
Tesla, which sent emails to affected customers citing the “exceptional circumstances,” joined many other companies trying to help Irma evacuees. Wireless carriers including AT&T, T-Mobile and Verizon waived overage charges for data customers in Florida. Nearly 200 Airbnb hosts opened their homes to evacuees for free.
But some critics said Tesla’s upgrade was less about good will than it was about greed. And even as Irma weakened, customers worried about Tesla’s ability to alter their vehicles on its own from afar.
That has raised security concerns, regardless of when the changes occur. As cars become more connected, the ability of criminals to remotely hack into them has also improved. At a meeting of the National Governors Association this summer, Elon Musk, Tesla’s chief executive, said one of the company’s top priorities was preventing “a fleetwide hack.”
The Irma upgrade was the first wireless enhancement that Tesla conducted for a particular event, said Colin Rusch, a managing director at Oppenheimer, the investment bank. More may come.
“You’re bringing a consumer electronics mentality to a durable-goods product,” Rusch said. “Adding incremental functionality is an ongoing process for Tesla. We’ll see them continue to participate in that over-the-air market.”