JDM is a term used by car lovers around the world for the Japanese Domestic Market (JDM). Japanese home market for vehicles is one of the largest ones in the world. For importers around the world, the term refers to vehicles and parts designed to conform to Japanese regulations and to suit Japanese buyers.

JDM stands for “Japanese Domestic Market,” meaning cars and parts made specifically for the Japanese market. Many U.S.-based Japanese car enthusiasts install JDM parts in their cars to improve performance and features. Some even import JDM cars to the U.S.

Compared to the United States where vehicle owners now own vehicles for a longer period of time, with the average age of the American vehicle fleet at 10.8 years, Japanese owners contend with a strict motor vehicle inspection and gray markets. According to the Fédération Internationale de l’Automobile, a car in Japan travels a yearly average of over only 9,300 kilometers (5,800 miles), less than half the U.S. average of 19,200 kilometers (12,000 miles). The low average mileage makes the JDM an attractive option for car importers around the world.

Japanese domestic market vehicles may differ greatly from the cars that Japanese manufacturers build for export and vehicles derived from the same platforms built in other countries. The Japanese car owner looks more toward innovation than long-term ownership which forces Japanese carmakers to refine new technologies and designs first in domestic vehicles. For instance, the 2003 Honda Inspire featured the first application of Honda’s Variable Cylinder Management. However, the 2003 Honda Accord V6, which was the same basic vehicle, primarily intended for the North American market, did not feature VCM, which had a poor reputation after Cadillac’s attempt in the 1980s with the V8-6-4 engine. VCM was successfully introduced to the Accord V6 in its redesign for 2008.

In 1988, JDM cars were limited by voluntary self-restraint among manufacturers to 280 horsepower (PS) (276 hp) and a top speed of 180 km/h (111.8 mph), limits imposed by the Japan Automobile Manufacturers Association (JAMA) for safety. The horsepower limit was lifted in 2004 but the speed limit of 180 km/h (111.8 mph) remains in effect. Most JDM cars have speedometers that register up to 180 km/h (111.8 mph) at the most.