Tesla is giving a boost to customers in the path of Hurricane Irma.

The electric carmaker says it is temporarily extending the range of some of its vehicles. In other words, drivers who are trying to leave Florida or another evacuation zone are now able to travel up to 40 extra miles before they need to stop and recharge.

The decision was reported earlier by Electrek. A Tesla (TSLA) spokesperson confirmed the move to CNNMoney on Sunday.

Here's how it works: Tesla remotely triggered a software upgrade for some cars in the southeast, where Irma is expected to cause significant damage, according to the spokesperson.

That update is allowing some Tesla batteries to travel for longer than they were previously able to.

When Tesla built the cars, it used software to restrict the car batteries' range and sold them for a cheaper price point.

Hurricane Irma: Live Updates

Customers who wanted to unlock the full capacity could later spend money to get the upgrade.

Tesla said it decided to temporarily extend the feature for free after one Irma evacuee requested it.

The free upgrade will last until September 16.

Some Tesla owners might have felt an advantage over drivers of gasoline-powered cars during the evacuations. There have been massive lines at pumping stations and widespread gas shortages throughout Florida.

Related: Gas stations on Florida's west coast are running out of fuel

No matter the type of fuel that powered their trips, people attempting to leave Florida via roadways still encountered miles of traffic jams. Millions have attempted to flee the state in the last few days.

About 6.3 million people were in mandatory evacuation zones, according to the state's division of emergency management. That makes it potentially the largest evacuation in U.S. history.

Irma made landfall in South Florida on Sunday as a Category 4 storm.

--CNNMoney's Peter Valdes-Dapena contributed to this report.