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Overview of Tesla Brake Technology
The latest Tesla vehicles use specially-adapted Brembo brakes. These brakes, which are manufactured by one of the most highly-acclaimed brake companies in the world, are very high quality and long-lasting.
Tesla vehicles also use a form of ‘engine braking,’ during which the motors turn into generators to charge the batteries and reduce energy waste. We’ll cover all of these systems in detail later in the article. But first, here’s how Tesla brakes work and a quick overview of their design.
What Kinds of Brakes do Tesla Cars Use?
Tesla vehicles use disc brakes, similar to what the vast majority of new American cars have. Disc brakes use a polished high-strength steel disc with louvers in the center for cooling.
The disc has a caliper that holds brake pads on both sides. When hydraulic pressure forces the caliper to close, the ceramic and heat-resistant brake pads cause friction and slow down the car.
Tesla brakes are extremely well designed, and Tesla brake pads have a remarkably long service life. And though the brakes themselves don’t differ much from ordinary automotive brakes, they are built with better engineering and higher-quality materials than many others.
Do Teslas Use Drum Brakes?
Absolutely not—Tesla cars don’t use drum brakes for any reason. Disc brakes are a superior system for cars, and drum brakes themselves have become increasingly rare on all cars over the years.
Do Tesla Cars Use Hydraulic Brakes?
Some Tesla vehicles use hydraulic brakes, but not all of them. Recently, vehicles equipped for full self-driving have come with Brembo fully-electric brakes. These brakes use electric actuators instead of hydraulic fluid pressure to actuate.
What Are the Benefits of Tesla’s Electric Brakes?
Electric brakes have several benefits over hydraulic systems. The most obvious is that, unlike hydraulic systems, which use fluid and high-pressure lines, an electric system never leaks. Additionally, the fluid can’t be fouled, there are no brake lines to rust, and it never needs a fluid change.
Tesla electric brakes eliminate an entire complex system of maintenance and testing and never require bleeding or pressure testing. Additionally, electric brakes can be controlled by the computer more precisely than hydraulic brakes.
Traditionally, electronically-regulated braking systems use an electro-hydraulic unit under the hood to proportion fluid pressure. These systems are complex and prone to failure, especially when there’s air in the lines.
Also, hydraulic systems lose some precision through the transfer of fluid through bent lines or lines that are clogged to various degrees. Over time, this limits the amount of control an electronic system can accurately exert.
Electric brakes suffer from none of these problems. They can be precisely controlled directly from the computer and send data back to it for interpretation. There’s no medium between the brake and the system—which increases accuracy and controllability.
This increased control also allows the brakes to be optimized, which extends brake pad life and increases stopping efficiency. These benefits, which also improve safety, made electric brakes a clear choice for Tesla.
Drawbacks of Electric Brakes
But what about redundancy? Is there any system in place to allow the driver to brake if the car runs out of battery power? Thankfully, Tesla thought through this design and added systems to ensure the safe and reliable operation of the brakes.
If your car runs out of power, the brakes will still work. This is because the vehicle’s safety systems operate using a different battery than the main power pack, which means it operates independently of the car’s overall charge level.
This system is likely more reliable than traditional hydraulic brakes, as it eliminates many mechanical failure points that break on conventional gas-powered cars all the time. You’d be in a similar situation if your brake fluid leaked out on the highway—and with the exception of the insufficient parking brake, you’d be out of luck.
What Does Tesla Regenerative Braking Do?
Regenerative braking isn’t a unique feature to Tesla vehicles, but their systems are still some of the best. Regenerative braking uses the excess energy produced by a moving vehicle to charge the batteries, thus slowing down the car.
Normally, all that motion energy is wasted through the brake pads and discs in the form of heat. Brakes get red hot and wear out with use, so why not tap into all that excess energy? It has to go somewhere—and regenerative braking simply puts as much as possible back into the batteries. How Does Tesla Regenerative Braking Work?
The operational principles of regenerative braking are simple, but they require special motors in the front wheels of Tesla vehicles. The preferred kind of motor in Tesla vehicles is the induction motor, which was designed by Nikola Tesla himself over a century ago. But these motors have no permanent magnets and thus can’t be used to generate electricity.
Brushless motors, which contain permanent magnets, can easily become generators. In fact, they already are. Brushless permanent magnet motors generate power when spun by outside forces (like a wheel) and become motors when using electricity to spin the wheel.
Essentially, Tesla vehicles use an automated switch to cut power to the front motors when decelerating. This allows them to use energy from the road to charge the batteries, as the momentum of the car keeps them spinning.
This also takes a lot of energy away from momentum and puts it into battery storage, which slows down the car without wear to your brake pads or discs. It’s an ingenious way to harness unused energy, extend service intervals, reduce maintenance costs, and increase the efficiency of the car.
Why Do Tesla Cars Slow Down So Fast?
If you’ve ever driven a Tesla, you’ll know that its deceleration is a lot closer to a gas car with a manual transmission than a run-of-the-mill automatic. These cars decelerate quickly when you take your foot off the gas and usually don’t coast much.
This is both a design characteristic that improves safety and a result of regenerative braking in action. The load on the front motors, which generates power, also slows down the car—which makes coasting impossible.
Although it may be annoying at first, it’s actually a great way to reduce your chances of having an accident. If you’re inattentive and take your foot off the pedal, the car won’t keep blasting down the road without direct input.
Also, coasting is illegal in many areas due to the fact that a coasting car is technically out of control. This was once a major issue with manual transmissions, as drivers who chose to coast instead of using engine braking wore out brake pads faster and increased their stopping distance on hills.
How Often Do Tesla Brakes Need Servicing?
Brakes perform an essential function and always have failure points, so they should be inspected at regular intervals. But Tesla brakes and brake pads have remarkably long lives, and there’s a good chance you’ll never need to replace them.
Many Tesla owners have gone 100,000 to 150,000 miles before replacing brake pads, which is orders of magnitude longer than traditional brake pads, which need replacing once every 25,000 to 65,000 miles.
Why Tesla Brakes Last So Long
Tesla brake pads and braking systems are exceptionally high-quality, which increases their lifespan by tens of thousands of miles. But the brakes themselves aren’t the primary reason why Tesla brakes last so long.
Regenerative braking is the key to the lifespan of Tesla brakes. Regenerative braking, which is operating most of the time, can do more than half of the braking for the car.
Once you learn how to drive a Tesla properly, you’ll be able to use regenerative braking for the majority of your everyday slowing down.
So when do you use regenerative braking instead of the brakes? Regenerative braking is useful for slowing down on the highway when you see traffic in the distance, slowing down on off-ramps, and coming up to stoplights when you’re not going too fast.
These also happen to be the situations where normal brake pads get the most wear—especially when slowing a hill descent. Brake pads get hottest, and brake rotors get warped when heated up over an extended period, which is exactly when regenerative braking works the best.
It’s a two-fold benefit. Regenerative braking saves the brake pads from the worst of their duties on long descents and generates the most power for the batteries during the same situations.
Is Tesla Regenerative Braking Efficient?
All things considered, Tesla regenerative braking would be more efficient than standard brakes even if it only recaptured 1% of the kinetic energy that’s normally lost in the form of heat. But it’s much better than that.
Tesla regenerative braking, in its earliest forms, captures about 80% of the kinetic energy involved in braking. After the second conversion back to power, Tesla regenerative braking has a net efficiency of about 64%. And these numbers are circa 2007 for the older Roadster models—so well done, Tesla.
About The Author
I've spent many years selling cars, working with auto detailers, mechanics, dealership service teams, quoting and researching car insurance, modding my own cars, and much more.Read More About Charles Redding