Race tires as opposed to qualifying tires.

Heavy duty duct tape used to temporarily repair hanging body parts, which might hinder aerodynamic features and decrease performance. Most commonly used on stock cars (e.g. NASCAR Nextel Cup), which use more paneling than Champ Car World Series vehicles and are accustomed to more contact.

Softer compound with better tread for wet-weather conditions. In dry conditions, these softer tires wear faster than harder compound tires with less tread. Also referred to as "Wets."

The time it takes an NHRA driver to react to the green starting light on the Christmas Tree, measured in thousandths of a second. The reaction-time counter begins when the last amber light flashes on the Tree and stops when the vehicle clears the stage beam.

Often called the "Reece" - is a pre-event period during which crews drive the rally route and special stages to prepare pace notes.

When displayed at the NASCAR or Champ Car World Series start/finish line, a red flag signifies an immediate halt of the session due to a dangerous condition such as a flooded track or a car blocking the track. Corner workers around the track will display black flags when this happens, and all cars are required to stop racing and slowly return to the pits. The lap in progress is discarded, and the field reverts to the order of the previous lap when racing resumes. If the race has run more that 50 percent of the laps, there is an option to declare a complete race if track conditions are not expected to improve. If a race has run less than 50 percent, it will be concluded on another date.

A normal road car (with extra safety equipment) used pre-event by World Rally crews to learn the route and stages.

An aluminum plate placed between the base of the carburetor and the engine's intake manifold with four holes drilled in it. The plate, used exclusively in NASCAR racing is designed to reduce the flow of air and fuel into the engine's combustion chamber, thereby decreasing horsepower and speed.

A vertical flap attached to a Champ Car World Series car wing for increased downforce. Please see Gurney Flap.

Modern Champ Car World Series engines are controlled by electronic "mapping" software that controls things such as fuel consumption and ignition timing. Rev limiting is used for two purposes: to keep the engine from exceeding its maximum rotational speed and exploding into bits of very expensive shrapnel, and to adhere to speed limit rules in the pit lane. The engine manufacturer sets maximum rev limits while the pit lane rev limiter is controlled by a pushbutton on the steering wheel.

Height the chassis sits from the ground on NASCAR and Champ Car World Series vehicles. Because of the relationship between the height of the ground-effect tunnels and their performance, maintaining optimum ride height is an important facet of car setup and design. However, it is hard to manage since the faster a car goes the more the aerodynamic effects press it to the ground. Many very complex methods are used to maintain a consistent ride height.

The specially prepared book of instructions, directions, maps and timings, issued to each World Rally car crew.

A race track with multiple left- and right-hand turns. Generally refers to permanent, purpose-built racing facilities. Can also refer to temporary street courses built on big city streets, which were popularized in the 1980's.

Large, sturdy bars designed to protect a driver's head if the car rolls over. Very functional in race cars but used more for style in production cars. Most production and race cars use anti-roll (or sway) bars as part of the suspension to prevent the excessive rolling in corners.

Champ Car World Series and NASCAR races begin after the pace car leaves the track while the cars are moving.

These flaps are sections at the rear of a NASCAR vehicle's roof that are designed to activate, or flip up, if the air pressure flowing across them decreases. In the case of a vehicle turning backwards, the tendency for an uninterrupted flow of air is to create lift. The roof flaps are designed to disrupt that airflow in attempt to keep the vehicle on the ground.

The spray trailing cars in wet conditions similar to the effect boats create across water.

Racing announcers use this to describe cars that make contact but don't crash. Also called "pushing and shoving."

A car is handling so well, a driver can use any racing line (or drive anywhere.) Sometimes, handling problems lead to a preferred line where the car handles better.

A car is running with little fuel. Teams qualify with a light load to achieve maximum speed.