Here's some help to better understand NASCAR

Don't know your drafting from your wedge? Just check out this glossary of racing terms so you can follow along in any conversation about NASCAR.

Updated: April 7, 2008, 5:31 PM ET

"The car checked out fine in the dyno, but it might not make any difference with the bear grease on the track. Throw in some dirty air, and all you can do is hope the scuffs and 200 mph tape will help the machine run flat-out."

Nextel Cup
Jonathan Ferrey/Getty Images for NASCARDon't feel left out when discussing NASCAR with thousands of your personal friends. Just brush up on this glossary.

To the serious race fan, the preceding statement makes perfect sense.

It translates to a car going through a dynamometer, which measures an engine's horsepower, racing on a track that has utilized patching material to fill cracks and holes (bear grease), and trying to make it through the turbulent air currents caused by fast-moving cars (dirty air) on tires that have been used at least once (scuffs) while racing as fast as possible (flat-out).

However, relative newcomers to NASCAR can't possibly understand some of the lingo. As a public service, here some definitions to help you along ...

Aero push: When following another vehicle closely, the airflow off the lead vehicle does not travel across the following one(s) in a normal manner. Therefore, downforce on the front of the trailing vehicle(s) is decreased and it does not turn in the corners as well, resulting in an "aero push." This condition is more apparent on the exit of the turns.

Aerodynamic drag: A number that is a coefficient of several factors that indicates how well a race vehicle will travel through the air and how much resistance it offers. Crewmen work to get the best "drag horsepower" rating they can, determining how much horsepower it will take to move a vehicle through the air at a certain mile-per-hour rate. At faster speedways teams strive to get the lowest drag number possible for higher straightaway speeds.

Apron: The paved portion of the racetrack that separates the racing surface from the infield. While listening to a race, you'll hear announcers talk about drivers shooting down on the apron. Now you'll know what they mean.

Back marker: Racers certainly don't want to be a back marker, which as implied means they have fallen completely off the pace and are at or near the back of the pack.

Balance: When a car doesn't tend to oversteer or understeer, but goes around the racetrack as if it's on rails, it's said to be in balance.

Clint Bowyer
Chris Graythen/Getty ImagesClint Bowyer leads a pack of cars while banking on the track at Michigan International Speedway.
Banking: The sloping of a racetrack, particularly at a curve or a corner, from the apron or inside of the track to the outside wall. Degree of banking refers to the height of a racetrack's slope at the outside edge.

Chassis: The combination of a car's floorboard, interior and roll cage.

Chute: A racetrack straightaway.

Dirty air: Any disturbance of the air around a car that impacts its aerodynamic performance. Dirty air can be displaced, used and discarded from other cars or it can come from running too close to the wall, causing a particular rig to lose control.

Donuts: One of the better slang terms on the circuit, donuts are dark, circular, indentation markings on the side panels of stock cars, frequently caused when one vehicle rubs up against another at high speed.

Downforce: A combination of aerodynamic and centrifugal force on each tire. The more downforce, the more grip the car has. But more downforce also means more drag and friction that will slow down the car. Downforce can be moved around by jacking weight into or out of each corner of the car.

Draft: The aerodynamic effect that allows two or more cars traveling nose-to-tail to run faster than a car running by itself. When one car follows another closely, the one in front cuts through the air that provides less resistance for the car in the back.

Drafting: The practice of two or more cars, while racing, to run nose-to-tail, almost touching. The lead car, by displacing the air in front of it, creates a vacuum between its rear end and the nose of the following car, actually pulling the second car along with it.

Drag: The resistance a car experiences when passing through air at high speeds. A resisting force exerted on a car parallel to its air stream and opposite in direction to its motion.

Jeff Gordon
Todd Warshaw/Getty ImagesWho are you wearing? Jeff Gordon models his trademark firesuit. Hot for spring.
Firesuit: Colorful, protective, fire retardant suit worn by NASCAR drivers emblazoned with the marks and logos of their sponsors.

Firewall: A solid metal plate that separates the engine compartment from the driver's compartment of a racecar.

Fuel cell: A holding tank for a race car's supply of gasoline. Consists of a metal box that contains a flexible, tear-resistant bladder and foam baffling. A product of aerospace technology, it's designed to eliminate or minimize fuel spillage.

Garage: The area on the infield of the racetrack where the race cars are parked and worked on by the teams.

Groove: The best route around a racetrack; the most efficient or quickest way around the track for a particular driver. The high groove takes a car closer to the outside wall for most of a lap, while the low groove takes a car closer to the apron. Road racers use the term "line." Drivers search for a fast groove, and that has been known to change depending on track and weather conditions.

Happy Hour: Slang term for the last official practice session held before an event. Usually takes place the day before the race and after all qualifying and support races have been staged.

Handling: Generally, a race car's performance while racing, qualifying or practicing. How a car "Handles" is determined by its tires, suspension geometry, aerodynamics and other factors.

Hauler: The long-haul trailer that stores and transports the NASCAR race cars and team equipment from the race shop to the race track. The so-called hauler is parked in the garage area in front of the team's garage and is used as a way station for team personnel.

Interval: The time-distance between two cars. Referred to roughly in car lengths, or precisely in seconds.

Lapped traffic: Cars that have completed at least one full lap less than the race leader.

Loose: Cars get loose when the front of the car has more grip than the rear and the rear tires have trouble sticking in the corners. This often causes the machines to fishtail as the rear end swings outward during turns. A minor amount of this can be a good thing at some tracks. A car that is too loose may have its rear end flair out toward the wall in turns. Sometimes referred to as "free" or "oversteer." In qualifying mode teams walk a fine line creating a setup that "frees the vehicle up" as much as possible without causing the driver to lose control.

Lucky Dog: During NASCAR races, the Lucky Dog is the first car that is one lap down from the leader(s). When the yellow caution flag come out, this car is led around the field and put into order as the last car on the lead lap, effectively getting a lap back without having to pass through the field. This rule was put into place as a safety precaution to prevent cars from racing to the start/finish line when the track is under caution.

Marbles: Debris blown to the upper corners of a track that consists of smatterings of rubber peeled from tires, dirt and gravel. Some drivers blame marbles for a loss of control, though centrifugal forces might have a little something to do with it. Graphic artists went to great lengths to replicate marbles for an air of authenticity in the animated flick "Cars." Also unaffectionately referred to as "loose stuff."

NASCAR: Acronym for "National Association of Stock Car Auto Racing," the league that sanctions, owns and operates the sport of stock car racing.

Jimmie Johnson
Matthew Stockman/Getty ImagesPit crews scramble to finish their work in their pit stalls along pit road at Kansas Speedway.
Pit road: The area where pit crews service the cars. Generally located along the front straightaway, but because of space limitations, some racetracks sport pit roads on the front and back straightaways.

Pit crew: Team members that work in the pits and on the cars during the races themselves. A total of seven team members go "over the wall" during pit stops, including: gas man (he pours the fuel into the car), catch can man (catches the empty can from the gas man), jack man (jacks the car up for tire changes), front tire changer (changes the tires), front tire carrier (passes along tire to changer), rear tire changer (changes rear tires) and rear tire carrier (passes along tire to changer). The pit crew is managed by the team's crew chief.

Pit stall: The area along pit road that is designated for a particular team's use during pit stops. Each car stops in the team's stall before being serviced.

Pit stand: Also sometimes referred to as the "war wagon." This stand, on the inside of the wall adjacent to the pit stall, is where key team personnel, most notably the crew chief and often the team owner, sit during the race and communicate strategy. It is outfitted with satellite television screens, timing and scoring information, radio controls and other communications relevant to race operations.

Pole position: Also referred to as "the pole." It is a term for the foremost position on the starting grid, awarded to the fastest qualifier.

Push: Also called "tight" or "understeer," push is when the rear of the car has more grip than the front, which can cause the front end to slide or "push" toward the wall in the corners. While it is true that the driver must get out of the throttle until the car catches so he can turn it to avoid hitting the wall, he also must get out of the throttle in a loose car to avoid the same fate.

Qualifying: Competition between teams for starting position within the race. In a NASCAR field, 43 cars qualify for the race. Lap times determine where in the field each car will start. The first or fastest qualifier is said to have won pole position.

Quarter panel: The sheet metal on both sides of the car from the C-post to the rear bumper below the deck lid and above the wheel well.

QuarterpanelsQuarterpanels on a Sprint Cup race car.
Restrictor plate: A restrictor-plate is a thin metal plate with four holes that restrict airflow from the carburetor into the engine. Placed between the base of the carburetor and the engine's intake manifold, it is used to reduce horsepower and keep speeds down. Currently, Talladega and Daytona are the only tracks that mandate the device. Without them, speeds could reach more that 210 mph and create a dangerous situation.

Setup: Slang term for the tuning and adjustments made to a race car's suspension before and during a race.

Short track: Racetracks that are less than one mile in length.

Silly season: Slang for the period that begins during the latter part of the current season, wherein some teams announce driver, crew and/or sponsor changes, and the attendant gossip that follows these changes. Jayski.com is the leading source of insider information on silly season.

Splash 'n' go: A quick pit stop that involves refueling the car with the amount of fuel necessary to finish the race and getting out of the pits as quickly as possible.

Speedweeks: The three-week period of time between late January and mid-February, beginning with the Rolex 24 Hours of Daytona Grand-Am race, and culminating with the Daytona 500, featuring a wide array of racing and motorsports activities at the Daytona International Speedway.

Spoiler: (Also referred to as a "blade.") The spoiler is a strip of aluminum that stretches across the width of a race vehicle's rear decklid. It is designed to create downforce on the rear of the vehicle, thereby increasing traction. However, the tradeoff, again, is that more downforce equals more aerodynamic drag, so teams attempt, particularly on qualifying runs, to lay the spoiler at as low an angle as possible to "free up" their vehicles for more straightaway speed.

Stagger: The difference in tire circumference from one side to the other. Placing larger circumference tires on the right side of a race car, for instance, helps it turn better through the corner on an oval track. Roll a Styrofoam coffee cup on a table and you will see stagger as the bigger top end travels farther than the smaller bottom.

Stickers: Slang for new tires. The name comes from the manufacturer's "stickers" that are pasted on the tire's surface.

Stop and go: A black flag penalty imposed in which the driver must stop in the team's pit stall and can go only when the official says so. It usually is assessed for speeding on pit road or for unsafe driving.

Superspeedway: A racetrack of one mile or more in distance. Road courses are included. Racers refer to three types of oval tracks. Short tracks are under one mile, intermediate tracks are at least a mile but under two miles and superspeedways are two miles and longer.

Trading paint: A term used to describe aggressive driving involving cars bumping and rubbing.

Telemetry: Data detailing key functions of a race car such as RPM. Commonly used for onscreen broadcast features.

Tight: Also known as "understeer." A car is said to be tight if the front wheels lose traction before the rear wheels do. A tight race car doesn't seem able to steer sharply enough through the turns. Instead, the front end continues through the wall.

Tri-oval: A racetrack that has a "hump" or "fifth turn" in addition to the standard four corners. Not to be confused with a triangle-shaped speedway, which has only three distinct corners. Talladega is a good example.

Turbulence: Air that trails behind a race car and disrupts the flow of air to the cars behind it.

Victory Lane: Sometimes called the "winner's circle." The spot on each racetrack's infield where the race winner parks for the celebration.

Wedge: Wedge is the amount of downforce that is applied diagonally from the left rear to the right front to help either tighten or loosen the car. Changing the wedge in one corner impacts the other three corners proportionally.

Sources: NASCAR, Bill Borden, Scripps Howard News Service