Open-wheel racing is any form of motorsport where the cars have wheels that sit outside the main body of the vehicle rather than tucked beneath fenders or bodywork. The wheels are fully exposed, and the driver typically sits in a narrow, open cockpit in a single-seat configuration. Formula 1, IndyCar, Formula 2, and Formula E are all open-wheel series, making it one of the most widespread and prestigious categories in global motorsport.
What Makes a Car “Open-Wheel”
The defining feature is simple: the tires are not enclosed by the car’s body. On a road car or a sports car racer, the wheels sit inside wheel wells covered by fenders. On an open-wheel car, each wheel extends outward on its own suspension arm, completely visible from every angle. This wasn’t always a racing-specific design. Before World War II, most street cars had wheels that protruded beyond the main body, usually covered by mudguards. As road car design shifted toward enclosed bodywork through the 1950s, the exposed-wheel layout became almost exclusively a racing configuration.
Beyond the wheels, open-wheel cars share several other traits. They’re single-seaters, with the driver sitting in a tight cockpit along the car’s centerline. The chassis is a carbon fiber monocoque, a single shell that serves as both the structural backbone and the survival cell protecting the driver in a crash. These structures are engineered to absorb and dissipate crash energy rather than transfer it to the driver. The cars are also low and narrow, with prominent front and rear wings that work like upside-down airplane wings to push the car down onto the track surface.
Why Exposed Wheels Change Everything
Leaving the wheels exposed creates a massive aerodynamic challenge. Research published in the journal Fluids found that the wheels of an open-wheel car account for roughly 40% of the car’s total drag. A spinning tire is a blunt, rotating object punching through the air, generating turbulent wake and complex vortex structures that disrupt airflow over the rest of the car. That’s a huge penalty compared to closed-wheel racers, where smooth bodywork guides air cleanly past the tires.
To compensate, engineers rely heavily on wings, diffusers, endplates, and other aerodynamic devices to generate downforce. The front wing alone can produce about 30% of the car’s total downforce, but its effectiveness drops when a wheel sits directly behind it, blocking airflow on the suction side. Endplates on the wing tips help steer air around the wheels to reduce both drag and lift. The result is a car that generates enormous grip at speed, enough to corner at forces that would cause a road car’s tires to slide immediately, but one that’s also sensitive to turbulent air from other cars. This is why following closely in open-wheel racing is notoriously difficult.
The Major Open-Wheel Series
Formula 1 is the highest-profile open-wheel championship in the world. Each team designs and builds its own car, pushing the boundaries of materials, aerodynamics, and hybrid power. Current F1 cars use a 1.6-liter turbocharged V6 paired with electric motors, producing a combined output of roughly 1,000 horsepower. The internal combustion engine contributes around 540 horsepower, with the electric components adding approximately 470 more. Top race speeds have reached 231 mph, and the cars accelerate from 0 to 60 mph in about 2.6 seconds.
IndyCar, the premier American open-wheel series, takes a fundamentally different approach. It’s a spec series: every team races a chassis built by the Italian manufacturer Dallara. Teams can develop components underneath the bodywork, but the visible aerodynamic package is standardized. This keeps costs lower and competition tighter. IndyCar engines are 2.2-liter twin-turbo V6 hybrids supplied by Chevrolet or Honda, producing 650 to 700 horsepower from the combustion engine plus 150 from the electric motor. On oval tracks like Indianapolis Motor Speedway, IndyCars are actually faster in a straight line, with qualifying speeds exceeding 236 mph. But on road courses, F1 cars are significantly quicker. When both series raced at the Circuit of the Americas in 2019, F1’s pole lap was nearly 14 seconds faster than IndyCar’s over the same layout.
Formula E is the all-electric open-wheel series. Cars start each race with about 52 kilowatt-hours of stored energy, enough to run a household fridge-freezer for two months, but the race itself can consume up to 90 kilowatt-hours. The difference comes from regenerative braking: when drivers brake, the electric motors reverse their role and act as generators, recapturing energy. This system is so effective that the rear axle has no traditional friction brakes at all. The battery can deliver up to 600 kilowatts (about 800 horsepower) and drivers must carefully manage their energy throughout the race. If they simply held the throttle wide open, they wouldn’t have enough charge to finish.
How Drivers Reach the Top
Open-wheel racing has a structured development ladder that functions like a league system. Most drivers start in karting as children, then progress into FIA-certified Formula 4 championships, which serve as the entry point from karts to car racing. In 2025, 13 separate F4 championships run across the Americas, Europe, and Asia. From there, drivers move into Formula Regional series, then into the international Formula 3 and Formula 2 championships, each step increasing the car’s speed and the level of competition. Formula 2 acts as the direct feeder to Formula 1, with the top performers earning seats or test opportunities with F1 teams.
Speed Compared to Other Race Cars
Open-wheel cars, particularly F1 machines, are the fastest circuit racers on Earth. At Silverstone, Lewis Hamilton’s 2015 F1 qualifying lap of 1:32.2 was more than seven seconds faster than the quickest lap set by Porsche’s 919 Hybrid, the dominant closed-cockpit prototype of the World Endurance Championship at the time. Seven seconds on a single lap is an enormous gap in top-level motorsport. The F1 car’s advantage comes primarily from its aerodynamic efficiency and low weight. Despite the drag penalty of exposed wheels, the overall downforce-to-weight ratio of an F1 car is unmatched.
That gap shrinks on longer circuits and at lower tiers of racing. When comparing sports car prototypes to lower-formula open-wheelers, lap times can be very close. The difference at the top, though, is stark: nothing on a closed circuit matches a current F1 car.
Safety Features in the Modern Era
Open-wheel racing was historically more dangerous than closed-cockpit racing because the driver’s head and upper body were exposed. That changed dramatically over the past two decades. The HANS device, introduced in 2003, restrains the driver’s head and neck during sudden deceleration, preventing the base-of-skull injuries that were once the leading cause of death in racing crashes. Energy-absorbing crash structures became mandatory in 2011, designed to crumple progressively and dissipate force before it reaches the survival cell where the driver sits.
The most visible modern safety addition is the Halo, a titanium structure mounted above the cockpit that was introduced in F1 in 2018 and has since spread to F2, F3, and other series. It was originally conceived to deflect a loose wheel assembly striking the cockpit area, but risk assessments showed it could protect against a much wider range of accident types, including cars going airborne and landing on top of another, or debris strikes at high speed. The Halo has been credited with saving lives in multiple incidents since its introduction, turning what would have been fatal impacts into survivable ones.
Inside the Cockpit
The steering wheel of a modern open-wheel car is closer to an aircraft control panel than anything you’d find in a road car. A recent Mercedes F1 steering wheel had 25 buttons and switches in addition to the clutch paddles and gear shift paddles. Five of those controls adjust braking alone: drivers shift brake balance between front and rear for individual corners, change the level of engine braking, and adjust how the brake balance shifts dynamically based on how hard they’re pressing the pedal. Three more switches control the differential, letting the driver fine-tune how torque transfers between the rear wheels at corner entry, apex, and exit. Other controls manage the power unit’s operating mode, which affects both engine performance and how aggressively the hybrid system deploys or recovers energy. A row of 15 LEDs across the top of the wheel tells the driver exactly when to shift gears.
Drivers make these adjustments lap after lap, often multiple times per lap, while cornering at speeds above 150 mph. The physical and cognitive demands are extreme: heart rates during a race routinely exceed 170 beats per minute, and drivers endure sustained lateral forces of up to 6 G in high-speed corners.