|Official name Mason-Dixon 500|
|Date May 17, 1981 (1981-May-17)|
Location Dover Downs International Speedway, Dover, Delaware.
Course Permanent racing facility 1.000 mi (1.609 km)
Distance 500 laps, 500.0 mi (804.6 km)
Weather Temperatures reaching up to 69.1 °F (20.6 °C); wind speeds up to 8 miles per hour (13 km/h)
The 1981 Mason-Dixon 500 was a NASCAR Winston Cup Series racing event that took place on May 17, 1981, at Dover Downs International Speedway (now Dover International Speedway) in the American city of Dover, Delaware.
During the preceding season, NASCAR had completely stopped tracking the year model of all the vehicles and most teams did not take stock cars to the track under their own power anymore. Only manual transmission vehicles were allowed to participate in this race; a policy that NASCAR has retained to the present day.
Dover Downs International Speedway, now called Dover International Speedway, is one of five short tracks to hold NASCAR races; the others are Bristol Motor Speedway, Richmond International Raceway, Martinsville Speedway, and Phoenix International Raceway. The NASCAR race makes use of the track's standard configuration, a four-turn short track oval that is 1 mile (1.6 km) long. The track's turns are banked at twenty-four degrees, and both the front stretch (the location of the finish line) and the backstretch are banked at nine degrees.
Five hundred laps took place on a paved track spanning a distance of 1.000 mile or 1.609 kilometres per lap. It took four hours and seventeen minutes for Jody Ridley to defeat Bobby Allison by 22 seconds in front of 40,000 live spectators. However, this victory was controversial because Allison's team blamed a scoring error for his loss (even though Allison himself did not actually protest the win).
The winner would win $22,560 in prize money ($59,430.57 when adjusted for inflation) while the last place winner would take home only $5,980 ($15,753.32 when adjusted for inflation). Two cautions were given out for 24 laps and the average racing speed was 116.925 miles per hour (188.173 km/h). David Pearson would acquire the pole position with a speed of 138.425 miles per hour (222.773 km/h).
All 32 drivers on the racing grid were American-born males. Benny Parsons would acquire a last-place finish on the first lap due to a crash with Dave Marcis. The lowest finishing driver to finish the race was Cecil Gordon; who was 42 laps behind the lead lap. The tenth-place driver would finish 20 laps down from the lead lap drivers. In today's NASCAR, he would have finished more towards the middle of the pack. There was a "communications meltdown" on lap 480 which put the race in jeopardy. Ridley's win was considered controversial because Allison claimed to have "won the race"; according to NASCAR team owner Harry Ranier.
* Driver failed to finish race
† signifies that the driver is known to be deceased