Accelerometer

A sensor placed in the driver’s earpiece that measures the forces experienced during a crash. Used to monitor impact severity and improve driver safety.

Adhesion

The grip between two stationary surfaces, like a tire and the track. Often used to describe the starting point of traction.

Aerodynamics

The way air flows around a car. INDYCAR teams manage aerodynamic elements to increase downforce for better grip and to reduce drag for more speed.

Apex

The inside point of a turn that drivers aim for to carry maximum speed through a corner.

Apron

The flat paved section separating the racetrack from the infield. It’s not intended for racing and is typically avoided at speed.

Blistering

A condition where a tire overheats and forms bubbles on the surface, reducing grip and durability.

Boost

Increased air pressure delivered to the engine by a turbocharger. On road and street circuits, INDYCAR drivers can activate push-to-pass for a temporary boost in horsepower.

Buckeye

The round external port on the side of an INDYCAR where the fuel hose connects during a pit stop.

Camber

The tilt of the wheels either inward or outward from vertical. Adjusting camber improves tire contact with the track during cornering.

Camshaft

An engine part that opens and closes the engine’s valves in sync with the pistons.

Chassis

The main structural frame of the car. INDYCAR uses the Dallara IR-18 chassis, designed for strength, safety and adaptability across all track types.

Checkered Flag

The black-and-white flag that signals the end of a race or session.

Clean Air

Undisturbed airflow that hits the front of the car, improving aerodynamic performance. Drivers in clean air often run faster lap times.

Cockpit

The section of the car where the driver sits. It includes the steering wheel, seat, safety harness and the protective aeroscreen.

Curb/Curbing

Colored sections along the inside of corners that define track limits. Drivers often use the curbs to help position the car but must avoid excessive contact.

Downforce

The vertical pressure created by a car’s aerodynamic design. Downforce pushes the car toward the track surface, improving grip and cornering ability.The vertical pressure created by a car’s aerodynamic design. Downforce pushes the car toward the track surface, improving grip and cornering ability.

Drafting

When a driver follows closely behind another car to reduce aerodynamic drag. Common on ovals, it helps increase speed and set up overtaking.

Drive-Through Penalty

A penalty requiring a driver to enter pit lane at pit speed without stopping, costing time and track position.

Drive Shaft

The mechanical component that transfers power from the engine to the wheels.

DRS (Drag Reduction System)

Not used in INDYCAR. A feature of some other series that reduces drag to aid overtaking.

DW12

The INDYCAR chassis introduced in 2012, named in honor of the late Dan Wheldon, who helped develop it.

ESS (Energy Storage System)

In INDYCAR, this refers to the low-voltage hybrid system that stores and redeploys energy during a race to enhance acceleration.

Fast Lap

The quickest single lap turned by a driver in a session.

Firestone

The exclusive tire supplier for the NTT INDYCAR SERIES. Their Firehawk tires are custom-engineered for road, street and oval racing.

Flat Spot

Damage to a tire caused by locking the brakes and skidding, resulting in a rough, uneven surface.

Fuel Window

The range of laps a car can run on a full tank of fuel. A key factor in pit strategy.

Full Course Yellow (FCY)

A caution period where all cars must slow down due to an on-track incident. The pace car leads the field until the track is clear.

G-Forces

The physical forces on the body during acceleration, braking and cornering. INDYCAR drivers routinely experience high lateral Gs.

Gearbox

The transmission system that allows the driver to change gears. INDYCAR uses paddle shifters on the steering wheel.

Grid

The starting lineup for a race, based on qualifying results.

Hairpin

A tight 180-degree turn, typically requiring hard braking and low-speed cornering.

Handheld Fuel Probe

The device used by pit crews to refuel cars during stops. It locks into the buckeye for a secure, fast connection.

Hybrid

A combination of internal combustion and electric power. INDYCAR’s low-voltage hybrid unit debuted in 2024 and enhances performance by storing energy and redeploying it on command.

Installation Lap

A systems check lap, usually done at the start of a session to ensure everything is working properly.

Livery

The paint scheme and sponsor branding on a car.

Marbles

Small pieces of rubber that accumulate off the racing line, reducing grip and making the surface slippery.

Out Lap

A driver’s first lap out of the pits. Typically slower as tires and brakes warm up.

Overcut/Undercut

Strategy terms used to describe when a driver pits earlier or later than a rival to gain an advantage based on tire performance or clean air.

Oversteer

When the rear tires lose grip before the front tires, causing the car to rotate more than intended.

Pace Car

Leads the field at reduced speed during caution periods.

Paddle Shifters

Levers on the back of the steering wheel that allow the driver to shift gears manually without removing their hands.

Pit Box

The designated area along pit lane where a team services its car during a stop.

Pit Lane

The area adjacent to the track where cars stop for fuel, tires and adjustments.

Pit Speed Limiter

A system that limits a car’s speed in pit lane to ensure safety.

Pole Position

The first spot on the starting grid, known as the NTT P1 Award in the NTT INDYCAR SERIES, earned by setting the fastest time in qualifying.

Push-to-Pass

A driver-activated system that provides a temporary increase in engine power on road and street courses, aiding in overtaking and defense.

Qualifying

The timed session that determines the starting grid for the race.

Red Flag

A signal to stop the session due to unsafe conditions.

Restart

The resumption of racing following a yellow or red flag period.

Ride Height

The distance between the bottom of the car and the track surface. Managed carefully to balance speed and downforce.

Road Course

A permanent, purpose-built racetrack with a mix of turns and elevation changes.

Rookie

A driver competing in their first full season in a given series.

Scrubbed Tires

Used tires that have already gone through one heat cycle. Often used for practice or early race stints.

Short Oval

An oval track typically under one mile in length. Requires quick reflexes and constant traffic management.

Sidepod

The side section of the car that houses radiators and other cooling components.

Slicks

Dry-condition tires with no tread. Provide maximum grip on a dry track.

Slipstream

Also known as the draft. The area of reduced air pressure behind a car, allowing another car to gain speed by following closely.

Steward

Race official responsible for enforcing the rules and issuing penalties.

Superspeedway

A large, high-speed oval track, such as the Indianapolis Motor Speedway.

Suspension

The system of springs and dampers that connects the wheels to the chassis, allowing the car to absorb bumps and maintain control.

Tow

A term for when a driver follows closely behind another car to reduce aerodynamic drag, helping gain speed. Similar to drafting but often used in oval racing context.

Traction

The grip of the tires while the car is in motion. Strong traction improves acceleration and cornering.

Understeer

When the front tires lose grip before the rear, causing the car to push wide in a corner.

Warm-Up Lap

A lap completed before the green flag to prepare the car and tires for race conditions.

Weightjacker

A driver-controlled tool used on oval tracks to adjust the crossweight of the car during a run. It helps fine-tune handling by shifting weight across the suspension while on track.

Wheel Gun

A pneumatic tool used by the pit crew to quickly remove and secure wheel nuts during pit stops.

Wheelbase

The distance between the front and rear axles of the car. Affects stability and cornering behavior.

Yellow Flag

Signals caution due to an on-track incident. Drivers must reduce speed and hold position until the incident is cleared.