Japanese domestic market

Fender mirror of Toyota Celsior (UCF20 JDM)

The term Japanese domestic market (JDM) is used by companies in Japan to refer to the local market for domestic goods and services, as opposed to the international, non-Japanese market. Within the automotive hobbyist import scene, this term, and the related term Japanese domestic model, most commonly refer to Japanese-brand automobiles and parts designed and constructed to conform to Japanese vehicle and equipment regulations and to suit Japanese market preferences.

JDM vehicles migrate to other markets through ordinary commerce and the grey market.

JDM cars were limited by a jishu-kisei (gentlemen's agreement) among manufacturers to 280 horsepower (PS) (276 hp) in 1988 and a top speed of 180 or 190 km/h since the late 1970's, both imposed by JAMA, mostly due to safety concerns and the latter due to concerns regarding bōsōzoku gangs. The horsepower limit was lifted in 2004. However, the speed limit of 180 or 190 km/h remains in effect, depending on the make and model of vehicle. Many JDM sports cars have speedometers that only go up to 180 km/h, even though the car would be capable of much higher speeds if not for the built-in limiter.

JDM vehicles often differ in features and equipment from vehicles sold elsewhere. For example, Honda has produced many different versions of the B18C 1, B16A and K20A engines for various markets worldwide. This is done due to varying emission regulations in different countries.

Vehicles built to JDM specifications may have stiffer suspensions and improved throttle response over vehicles built for different markets, due to differing driving styles and different road types. For example, the USA features long highways where a smoother ride would be preferable, while Japan's roads are short and twisty, where a stiffer suspension is desired for improved handling capability. For the US and European market versions, some features may be removed in order to stay below a certain pricing goal for the car, such as using a conventional rear suspension instead of a double wishbone suspension and lack of electronic devices like Active Yaw Control. Furthermore, engine power of JDM sports cars is sometimes reduced because of stricter emission standards in other countries.

There are safety hazards associated with using JDM headlamps in countries where traffic flows along the right side of the road, because JDM headlamps, engineered for use on the left side of the road, fail to light the right-side driver's way safely ahead while blinding oncoming motorists.

JDM cars are allowed for importation into the United States of America but must be approved by the National Highway Traffic Safety Administration (NHTSA) and then smog checked by the Environmental Protection Agency (EPA) after this, the car receives a sticker of approval, and then can be registered with a U.S. VIN Vehicle Identification Number. This procedure is not necessary if the car in question is already on the NHTSA approved list of Grey import vehicles, these cars are ones that already have a similar U.S. counterpart or have been crash tested and proven that they meet Department of Transportation (DOT) safety standards. Cars that are sold in America have a 17 digit VIN number while their Japanese counter parts have a 10 digit VIN number. There has been a common problem of people "swapping" their vehicle's USDM (17 digit) VIN numbers on to the JDM (10 digit) chassis. This is against federal law and is a felony.

See also

• JDMUnderground Philippines - A community of JDM Enthusiasts in the Philippines
• CLUB DEFEND a JDM Blog
• JDMTurkiye.com
• jdmhood.com El Salvador jdm club
• Import scene
• Economy of Japan