Stock Cars

A stock car in the original sense of the word is an automobile which has not been modified from its original factory configuration. This term was used to differentiate such a car from a race car, a special, custom-built car designed only for racing purposes with no intent of its ever being used as regular transportation.

When NASCAR was first formed to regulate stock car racing, there was a requirement that any car entered be made entirely of parts available to the general public through automobile dealers, and that all cars must be from a model run of which at least 500 cars of that model were sold to the general public. In NASCAR's early years, the cars were so "stock" that it was commonplace for the drivers to drive themselves to the competitions in the car that they were going to run in the race.

This was eventually modified, however, primarily in the interest of safety, as race drivers are subjected to forces unheard of by drivers of cars in ordinary use, and require a far higher level of protection than is normally afforded by truly "stock" automobile bodies. Modern racing "stock" cars are stock in name only, using a body template modelled after currently-available automobiles, but the chassis, running gear, and equipment have almost nothing to do with those of ordinary automobiles.

Modern stock cars superficially resemble standard American family sedans, but are in fact purpose-built racing machines built to a strict set of regulations governing the car design ensuring that the chassis, suspension and such are architecturally identical on all vehicles. Ironically, these regulations ensure that stock car racers are in many ways technologically less sophisticated than standard cars on the road. For example, NASCAR (the premier stock car organisation in the US) requires carbureted engines in all of its racing series, while fuel injection is now universal in standard passenger cars.

Engines, whilst containing varying components from the various manufacturers who compete in the series, are of fixed size, and are generally designed to ensure all entrants have near-equal vehicles. There are several categories of stock car racing, each with slightly different rules, but the key intention of cars that look like production cars, but with near-identical specifications underneath, remains true.

The closest European equivalent to stock car racing is probably touring car racing, though these are raced exclusively on road circuits rather than ovals.