Formed in 1948, the National Association for Stock Car Auto Racing, commonly referred to by the acronym NASCAR, is a privately owned business that sanctions and governs a range of automobile racing events. The rules and regulations that govern these races are issued by NASCAR officials before each racing series and given to NASCAR members but not generally made available to the public.
The reported weight limit for a 2008 NASCAR Nationwide Series car was 3,400 pounds. This includes everything a car needs to have to be ready for the race, except the driver. The car must be weighed by race officials and must be no lighter than 3,400 pounds when all required liquids and equipment are on board. It can, however, weigh as much over this amount as is desired.
NASCAR cars must also weigh at least 1,625 pounds on the front-right and right-rear sides of the car. This rule prevents cars from having too much weight on the left side of the car. Because NASCAR races are with left-hand turns, drivers would want to have more weight on the left side of the car to aid in turning. The right-side rule limits this advantage.
NASCAR cars are weighed at different times before a race to ensure the car complies with the requirements. Cars are weighed by NASCAR officials before each weekend's race events begin, beginning with a pre-practice weigh-in. Another weigh-in is conducted before qualification, and a third before the actual race, assuming the car is not impounded after qualifying. All weigh-ins are performed on NASCAR's official scales.