Hot wheels. Our wheels are constructed from machined forged aluminum alloy, making them extremely lightweight while giving you better performance. The unique design of the spokes leans clockwise on the right side of the car and counter-clockwise on the left.

Safety

Protection from the Ground Up

A well-built car considers safety long before it meets up with slick surfaces or red-light runners. At Tesla Motors, we design our cars to prevent collisions and to minimize damage should one be unavoidable.

Four Outstanding Safety Features: The Tires

When driving, tires are your only contact with the outside world, so we take tires very seriously. The Tesla Roadster starts with superior Yokohama tires, and fits them onto custom and directional wheels. Our independent, double-wishbone suspension ensures that each wheel works independently with optimal tire-to-ground contact at all times. And because tire pressure is crucial to a balanced drive, our VDS (Vehicle Display System) comes standard with a tire-pressure monitoring system.

The Most Crucial Few Seconds Behind the Wheel

No car manufacturer can prevent accidents, but we’ve done everything in our power to minimize the likelihood of one occurring. Should the unthinkable happen, you’ll be reassured to know that we’ve already thought about it, many times over. Our 4-channel anti-lock braking (ABS) system offers shorter stopping distances and gives you full steering control with no lockup. The car’s side beams are positioned to offer extra safety to the exact area where you sit. Plus, we outfit every car with driver and passenger airbags, roll-over protection, and energy-absorbing sections in both the front and back of the vehicle.

Safety testing in Arvidsjaur, Sweden

In January 2007 our engineers traveled with one of the prototype Tesla Roadsters to Arvidsjaur, Sweden, to perform ABS and other safety testing. Located 110 km south of the Arctic Circle, Arvidsjaur is one of Europe’s most extreme environments and a location favored by car manufacturers worldwide for cold weather testing. We used frozen lakes and icy back roads in the area to put the Tesla Roadster through its paces. For a sample of some of the tests we performed, take a look at the videos below or read our blog post.

ABS
The car is driven at high speed over a split surface (otherwise known as a "split-mu" course), where one half of the car is over a heated patch of asphalt (high-mu) and the other half of the car is over ice (low-mu). The ABS system detects the wheels locking up on the slippery, icy side and automatically reduces the braking pressure on that side. This ensures the car will remain stable and stop in a straight line when the brakes are applied. Watch ABS test video. ( Free QuickTime player required to view video. Videos depict professional drivers on closed course. Do not attempt.)

Throttle
We take another high-speed drive on ice, this time around the circular track that demonstrates fine turning of the Tesla Roadster’s throttle control. Traction control is turned off, so you will notice the car sliding to some degree. Watch ice driving: wide view or watch ice driving: car chase view. (Free QuickTime player required to view video. Videos depict professional drivers on closed course. Do not attempt.)

With Charging, It’s Safety First

We’re committed to making sure the charging process and the batteries themselves won’t pose a safety issue to you, your passengers, or anyone stumbling around in your garage.

For starters, the plug on the charging unit only becomes “live” when it is properly connected to the car and both the charging unit and the car have “talked” and agreed the connection is safe to allow the electricity to flow through it. As a backup, the charging connector is designed such that you cannot touch any metal on the charging pins.

The EVSE in your garage protects against many kinds of faults, including ground faults, strain on the cable, and the presence of smoke in your garage. Whenever any fault is detected, charging is stopped and the cable is deactivated.

Energy Storage is All About Safety

Tesla Motors’s engineers selected cells from a reputable Fortune 500 battery supplier that has produced billions of safe, reliable, Li-ion batteries. We combined this basic proven cell technology with our own unique battery pack design to provide multiple layers of protection. Our design ensures that should any cell fail catastrophically, adjacent cells do not. This is true regardless of whether or not the battery pack cooling system is running. (The cooling system in the Energy Storage System exists to increase the battery pack’s life -- we don't depend on it for safety.)

We then collaborated with an outside firm known for expertise in lithium ion battery safety to perform hundreds of tests to validate the safety of our design. In these tests, we set out to simulate a worst-case scenario in which a cell develops a serious malfunction. In each test, we set a cell on fire in the middle of a Tesla Motors battery pack (by heating the heck out of it) and observed the results. Our design contained these failures to a single cell, demonstrating that malfunctions wouldn’t spread.

The Battery Safety Monitor, mounted inside the battery pack’s protective enclosure, measures voltage, current, acceleration, tilt, smoke, moisture, and more. Like the controller for an airbag, the Battery Safety Monitor responds to an emergency - in this case by automatically disconnecting the battery pack from the vehicle and shutting down power to the car and to all electric cables in the car.

None of the Tesla Roadster’s high voltage systems are accessible to accidental contact outside their protective enclosures and jacketed cables. Only with special tools can someone gain access to any high-voltage components. Our high-voltage systems are enclosed, labeled, and color-coded with markings that service technicians and emergency responders already understand.

Designing a safe, large lithium ion battery is difficult, but not impossible.