What's a JDM?

What’s a JDM?

JDM refers to cars built for use on Japanese roads. It is a common misconception that JDM refers to any Japanese car, however this is not true, as it only applies to those models manufactured specifically for the Japanese domestic market. Compared with the United States where vehicle owners are now holding on to their vehicles for longer, with the average age of the American vehicle fleet at 10.8 years, Japanese owners contend with a strict motor vehicle inspection. 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).

Japanese domestic market vehicles may differ 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 rather than long-term ownership which forces Japanese carmakers to refine modern technologies and designs first in domestic vehicles. For instance, the JDM 2003 Honda Inspire featured the first application of Honda's Variable Cylinder Management system. 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 by Honda to the Accord V6 in its redesign for 2008.

In 1988, JDM cars were limited by voluntary self-restraints among manufacturers to 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

The real pivot toward JDM vehicles came in the 1990s, when magazines like Sport Compact Car and Super Street focused on the growing enthusiasm for Japanese “tuner cars” and the enthusiast culture forming around them. The Acura Integra, Honda Civic, Mitsubishi Eclipse, and Nissan 240SX were among the most common models featured in these magazines. 

The growing popularity of those American market magazines conveniently coincided with a wave of Japanese supercars coming to U.S showrooms, such as the all-new Honda NSX (badged as an Acura in the U.S.) and Mitsubishi 3000GT VR4. The 1990s also saw substantial horsepower and chassis upgrades to existing U.S-market Japanese sports cars like the RX-7, Supra, and 300ZX, many of them now featuring twin-turbo engines and successfully competing in high-profile motorsports activities.

By the early 2000s additional JDM models had made the leap to U.S. showrooms, including the all-wheel-drive Subaru Impreza WRX STI and Mitsubishi Lancer Evolution (or Evo). The Honda S2000, a new rear-wheel-drive sports car with a 6 speed manual transmission and 9,000 rpm redline, added to the momentum, as did a little movie called The Fast and The Furious. 

This relatively low-budget, performance-car-themed film put a heavy emphasis on JDM cars sporting numerous aftermarket car parts. Honda Civic and Mitsubishi Eclipse variants, utilizing large spoilers and nitrous oxide, along with true JDM cars like the right-hand drive Nissan Skyline GT-R, helped validate the film with JDM fans. The Fast and The Furious was a huge box-office success, inspiring more than 10 sequels/spin-offs, and popularizing terms like nitrous oxide, supercharger, and twin turbo.

In 2004, importing JDM cars became popular in Canada as highly sought-after vehicles, such as the 1989 Nissan Skyline GT-R, became eligible to import under Canada's 15-year rule. In contrast, importing grey market vehicles into the United States is much more difficult. To avoid regulatory problems, most private individuals wait until EPA restrictions no longer apply to the desired vehicle, which is done on a rolling 25-year cycle.

Note that all JDM vehicles are right hand drive, and left-hand gear shift, so may take some adjustment for those only ever having experienced left hand drive vehicles.

This Sunday, May 22, JDM open house and car meet at Kuruma Imports, Miami.