Will your Smartphone replace your car key?

NEWYou can now listen to Fox News articles!

The new Tesla Model 3 has lots of eye-opening features that distinguish this fully-electric car from other hybrid and electric vehicles, including a single touch screen that replaces the traditional dashboard full of buttons and displays.

Still, perhaps the first big difference many Model 3 drivers will notice is this Tesla's lack of a traditional key fob. That familiar feature—along with the door locks and start button—has essentially been replaced by the Tesla smartphone app (shown at top).

The Model 3 can sense an authorized driver’s smartphone from up to 30 feet away, turning a driver's smartphone into a virtual key, allowing him or her to set the Model 3 doors (and even the trunk) to automatically unlock when approaching the car; the doors lock themselves when the driver walks away from the car. Starting the Model 3 is as simple as shifting out of Park.

But it could be a few years before other automakers widely adopt the virtual key, as car companies and smartphone manufacturers struggle to overcome some basic issues with the technology, according to industry suppliers and researchers CR spoke to.

More From Consumer Reports

Meanwhile, automakers and phone manufacturers are still working to collaborate on standards so that a software update or security breach on your smartphone doesn't render your virtual car key useless and your car undrivable.

There's also the basic question of how well today's smartphone-as-car-key technology works. For instance, CR's testers found that the Model 3's virtual key isn’t always as convenient or as secure as a traditional key fob. (Read about CR's test of the Tesla Model 3's virtual key.)

Virtual Keys Are Still Evolving

Despite the potential benefits of virtual keys—no key fob to carry or lose (and replace for a steep price), and the fact that you can lend someone your car just by granting access through an app—some experts think it’s too soon to implement the technology widely.

“I think you want to be very careful before you roll out something radically different, [because] there may be a gap in security or convenience," says Michael Crane, head of vehicle body and security for the automotive supplier Continental.

The limitations of current virtual-key technology are among Crane's top concerns. For instance, the Model 3 virtual key relies on Bluetooth Low Energy, or BLE, to connect with the car. But BLE doesn’t work unless the phone is turned on and the Tesla app is open and active on the phone.

Our testers occasionally found themselves unable to open the Model 3's door when they had closed the app—the modern equivalent of fumbling for keys at the bottom of a purse.

There are other drawbacks to virtual keys. What happens when your smartphone battery dies? Can you still access and drive your car if you lose your phone? And what do you do when you leave your car with a parking attendant, say, in a public garage or at a venue with valet parking, or take it to a car wash?

The Tesla Keycard
Given those scenarios, Tesla provides Model 3 owners with a backup keycard (shown below) to carry in a purse or wallet. (The Tesla Model S and Model X come with a regular key fob.)

But the keycard isn't an ideal solution. To lock or unlock the car, a driver must must swipe the keycard along the pillar next to the driver’s seat. The Model 3 doesn't come with a traditional ignition switch or push-button start, so drivers must also tap the key behind the front-seat cup holders to "start" the car. Neither spot is well-marked. Imagine having to explain that routine every time someone borrows your car.

There’s also an issue with the smartphone itself: The lifespan of a car is far longer than that of any smartphone, so suppliers will have to work with phone manufacturers to ensure that their virtual-key technology remains compatible over the years.

“The next time I get an upgrade pushed to me by Apple, I don’t want my virtual key to be inoperative,” Crane says. That’s why he expects most cars will still come with key fobs even if they offer a virtual key.

Keeping Cars Secure

Automakers also have to be sure that a smartphone-based key is as secure as a traditional key fob, and that requires working with smartphone manufacturers.

“The security of the system is now relying on the security of your phone,” says Karl Koscher, an automotive-security researcher at the University of California at San Diego. For instance, it might be possible for hackers to access the virtual key of a car owner who has visited a malicious website or downloaded an app with malware.

"The good news is that smartphone makers generally patch known security flaws with software updates more often than automakers fix faulty hardware," Koscher says.

However, software updates can't yet fix some inherent flaws in current smartphone-as-car-key technology, which could make it easy for the wrong person to get access to a vehicle.

The traditional keyless entry fobs used by most cars today rely on RF (radio frequency) technology, which sends a radio signal to a receiver inside the car that can determine the location of the key. In most cases, drivers can’t start the car unless the key is inside the vehicle. “Within millimeters, we know whether that key is inside or outside the car,” Crane said.

However, the latest smartphone-based keys use different technology. The Model 3’s BLE setup can anticipate a driver’s arrival and unlock the car from a distance of up to 30 feet, which is shorter than a traditional RF keyfob’s range. At closer range, the vehicle can’t determine whether the key is inside or outside the car. That means there’s a greater risk of the vehicle being stolen as the owner approaches or for a child to start the car while a parent is just outside the vehicle.

CR Tests the Tesla Model 3 Virtual Key

We left a smartphone equipped with the Tesla virtual-key app 5 feet outside the driver’s door of our test vehicle and attempted to start the car. Even though the phone wasn’t inside the Model 3, we were able to start it and drive away. (The car would not start when the phone was more than 5 feet away.)

During a 10-mile trip without the phone or the backup keycard, no messages on the car’s display warned us that the key was not in the vehicle, and the Tesla app didn’t display any notifications that the car had been driven away.

That's in contrast to what we've seen with other cars. Nearly every vehicle we’ve tested will warn the driver if the car is running but the key is absent.

For instance, when we tried the same test with a 2018 Mazda CX-5 and a 2018 Ford Expedition—both equipped with a traditional key fob—we couldn’t start either vehicle when the fob was more than a half-inch outside the driver’s door.

We also tested a 2018 Chevrolet Bolt equipped with GM’s KeyPass BLE-based virtual key. Although the app let us unlock the doors, the system still required a key fob to be present for the car to start.

Tesla says that it has plans to improve the accuracy of its BLE-based system. The company is also rolling out a software update for its virtual-key function so it unlocks the doors when any handle is pulled and opens the trunk when the button on the lid is pushed.

The Future of Virtual Keys

Despite issues with smartphone-as-car-key technology, automakers are still moving forward.

Mercedes-Benz has offered a phone-based key for the European version of the E-Class since 2016. A similar option will be available on the European version of the 2019 Audi A6, although it will be compatible only with Android phones.

Both systems use near field communication (NFC) to operate. Unlike BLE, NFC works even if a phone’s battery is dead. (NFC lacks the range of BLE or a traditional RF key fob, so the driver must hold the phone against the door handle to unlock the car and place the phone in a specific spot on the dashboard to start the car.)

Other automakers are getting in on the action. The Lincoln Way app for the Lincoln Aviator, for instance, will mimic such traditional key-fob functions as unlock and chirp, and it can even store driver profiles for various comfort settings. Should the phone battery die, the driver can still access the SUV using an exterior keypad. This decades-old Ford/Lincoln feature handily gets around concerns raised for other systems.

Zipcar currently allows app-based access to its rental vehicles, and some traditional rental-car companies in the U.S. are also pilot-testing app-based access so drivers can check in on their phones and get going without a trip to the counter. Tesla has said that its virtual keys will help drivers share their Model 3s with other drivers using the company’s own ride-sharing platform.

Although Tesla is the first automaker in the U.S. to offer smartphone-as-car-key technology, Crane is confident that similar systems will roll out in most cars over the next decade, starting with luxury vehicles.

“I’m absolutely convinced you will see this trickle down from the top, from the premium segment,” he says, as have many advanced technologies over the years.

Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2018, Consumer Reports, Inc.