Compared to the United States where vehicle owners are now owning vehicles for a longer period of time, with the average age of the American vehicle fleet at 10.8 years,[1] Japanese owners contend with a strict motor vehicle inspection system which forces them to pay more each year to own a car, or to sell or scrap it as the costs increase. Compliance encourages a burgeoning export business in legitimate and gray markets. According to the Fédération Internationale de l'Automobile, a car in Japan travels a yearly average of only 9,300 kilometers (5,800 miles), less than half the U.S. average of 19,100 kilometers (12,000 miles).[2]
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-restraints among manufacturers to 280 horsepower (PS) (276 hp) and a top speed of 190 km/h (118.1 mph), limits imposed by the Japan Automobile Manufacturers Association (JAMA) for safety. The horsepower limit was lifted in 2004 but the speed limit of 190 km/h (118.1 mph) remains in effect. Many JDM cars have speedometers that register up to 180 km/h (111.8 mph) (certain Nissans go up to 190 km/h, and the GT-R has a mechanism that removes the speed limiter on a track) but all have speed limiters.
JDM cars usually have stiffer suspensions and improved throttle response because the roads wind over hilly terrain.[citation needed] Conversely, American drivers prefer smoother rides because of interstate systems covering thousands of miles. Japanese manufacturers also remove certain innovations to keep US and European prices down, such as using a conventional rear suspension instead of a double wishbone suspension and eliminating electronic devices such as Active Yaw Control. Finally, JDM engine power is sometimes reduced d because of stricter emission standards in other countries.
source: id.wikipedia.org
