Every brake, in a road car or a race car, does the same basic job: it turns the car’s movement energy into heat. When the driver presses the pedal, hydraulic fluid pushes pads against discs that spin with the wheels. The friction between them slows the wheels, and the energy of motion becomes heat in the discs and pads.

An IndyCar has to do that far more violently than a road car. It’s light, very fast and has lots of aerodynamic downforce, which pushes the tyres into the track and gives them much more grip. That grip means the car can slow down much harder without the wheels locking. The brakes have to be strong enough to use all that grip, lap after lap, without overheating or wearing out.

There’s also no anti-lock braking system (ABS) in IndyCar. In a road car, ABS stops the wheels locking if you brake too hard. In an IndyCar, the driver has to control that with their right foot. Too little pressure wastes time. Too much locks a wheel, flat-spots the tyre and can send the car straight on at the corner.

The brake bias is one of the most important settings. It controls how much of the braking force goes to the front wheels compared with the rear. More front bias makes the car stable but can lock the front tyres; more rear bias helps the car turn but can make the rear step out. Drivers adjust it during a race as fuel burns off, tyres wear and conditions change.

Since 2017, every car’s brake components have come from a single supplier, Performance Friction Corporation (PFC), under an exclusive deal with the series. A single supplier keeps costs down and means no team has an advantage from better brake parts. The current package uses six-piston calipers at both the front and rear, and the same brake specification has been used at every type of track.

Road cars mostly use iron brake discs. IndyCar has used carbon brakes at every track since 2012, when the current Dallara car was introduced. Carbon brakes are made from carbon fibre bonded in a carbon matrix, and they have three big advantages for racing.

First, they’re light. Brakes are “unsprung” weight, meaning they move with the wheels rather than being supported by the suspension, so saving weight there improves handling. Second, they cope with extreme heat. Carbon brakes can run far hotter than iron ones without losing strength, which is why you sometimes see them glowing orange on TV. Third, they grip very strongly once warm, giving huge stopping power.

The catch: temperature

Carbon brakes have a downside: they only work well within a temperature window. When they’re cold, they don’t grip properly, so the car won’t stop as expected. That’s a real danger on the first lap after a pit stop, after a safety car, or at the start of a race. When they’re too hot, they wear much faster. Teams manage this with brake cooling ducts, choosing larger or smaller openings depending on the track and the weather.

Making the brakes last a race

Unlike tyres and fuel, brakes aren’t changed during a pit stop. The discs and pads fitted before the race have to last the whole distance. On a demanding street circuit, that means teams have to balance cooling, wear and performance carefully. Too much cooling and the brakes may be too cold to work well; too little and they may wear out before the finish. If a driver starts to feel the pedal going longer or the car pulling to one side, it can be a sign the brakes are overheating or wearing unevenly, and the team may ask them to ease off.

Before 2012, carbon brakes weren’t used at every event. Moving to carbon everywhere with the current Dallara chassis simplified things for teams and brought IndyCar in line with other top single-seater series. The move to a single supplier in 2017 did the same for cost and consistency.

Since mid-2024, IndyCars have had a hybrid energy recovery system. A motor generator unit (MGU) and a bank of 20 supercapacitors sit inside the bell housing, between the engine and the gearbox. The system weighs 42.5 kg.

When the car slows down, the MGU works as a generator. Instead of all the braking energy turning into heat at the discs, some of it is turned into electricity and stored in the supercapacitors. That can happen automatically, based on how much the driver lifts off the throttle and presses the brake, or manually: drivers have a paddle on the steering wheel that changes how much energy is recovered.

The stored energy is then deployed with a button on the steering wheel, adding up to 60 horsepower. The supercapacitors can fully charge and discharge in about 4.5 seconds. On road and street courses, combined with the push-to-pass system, drivers can have more than 120 extra horsepower available.

What this means for braking

Energy recovery adds a small amount of extra “braking” through the drivetrain, acting on the rear wheels as the MGU generates electricity. Drivers and engineers have to account for that when setting brake bias, because the amount of recovery changes with how the driver uses the paddle. It’s one more thing a driver has to manage while braking at the limit. For how hybrid systems work more generally, see our explainer on hybrid power in racing, which covers why NASCAR hasn’t followed IndyCar down this path.

How IndyCar compares with F1 and road cars

Formula 1 also uses carbon brakes, but its much more powerful hybrid system means it uses an electronically controlled “brake-by-wire” system on the rear axle, which blends energy recovery and friction braking automatically. IndyCar’s set-up is more traditional: the driver’s foot controls the friction brakes directly, with the hybrid system’s recovery added on top. A road car, by comparison, uses heavier iron discs, power assistance and ABS, all designed for safety and long life rather than maximum performance.

That makes IndyCar braking something of a middle ground. It’s more direct and less electronic than F1, which many drivers enjoy for the feel it gives, but far more extreme than anything on the road. For the engineering basics behind the power these brakes have to control, see our guide to how car engines work.

IndyCar is unusual because it races on three very different kinds of track, and each puts different demands on the brakes.

Street circuits such as St. Petersburg, Long Beach and Detroit are the toughest on brakes. They have long straights leading into slow corners, often with bumpy surfaces that make it easy to lock a wheel. Teams use bigger cooling ducts and watch brake temperatures closely.

Pit-lane braking

Every track has a pit-lane speed limit, and drivers must be at or below it by the time they cross the line at the pit entry. Arriving too fast earns a penalty, while braking too early costs time. Drivers use a speed limiter button once they’re down to the limit, but getting there from racing speed is down to precise braking. It’s a small moment, but in a close race, a well-judged pit entry can gain or lose several places.

On a big oval like Indianapolis, drivers barely touch the brakes during green-flag running. The biggest braking moments come when entering the pit lane, where cars have to slow from racing speed to the pit-lane limit. That’s why IndyCar has looked at an oval-specific brake package. The current system uses the same components everywhere, but in November 2025 the series tested a smaller, lighter oval caliper from PFC at Indianapolis, with four pistons at the rear instead of six, intended to give drivers better pedal feel when slowing for the pit lane. It was expected to be introduced for 2026.

Good braking isn’t just about pressing the pedal hard. The best IndyCar drivers hit the brakes very hard at first, when the car is fast and the downforce is pushing the tyres into the track, and then gradually release pressure as the car slows and grip drops. That technique, often called trail braking, lets them carry more speed into the corner while keeping the tyres just short of locking.

Drivers also need a precise feel through the pedal. Without ABS, the only thing stopping a locked wheel is the driver’s foot. They also have to adjust for changing conditions: brakes that aren’t yet warm after a pit stop, a heavier car at the start of a stint, worn tyres at the end of one, and the extra rear braking from the hybrid system. Getting all of that right corner after corner, for two hours, is part of what separates the best drivers from the rest.

Braking and overtaking

Most overtakes in IndyCar happen under braking. A driver who can brake later than the car ahead, while still making the corner, can pull alongside and take the position. Push-to-pass and the hybrid boost help get close on the straight, but the move itself is usually completed in the braking zone. That’s why commentators talk about drivers who are “strong on the brakes”. For more on why passes sometimes go wrong, see our explainer on what causes crashes in motor racing.

Brake jargon, decoded