January 21, 2005

JAMA Encourages Daily Vehicle Monitoring to Support *Low-Sulfur Diesel Fuel Supply
*(Sulfur content=10ppm or less)
-on Web site and through poster campaign-

In response to the provision by fuel suppliers of low-sulfur diesel fuel (i.e., with sulfur content of 10ppm or less) beginning this month, the Japan Automobile Manufacturers Association (JAMA) has posted on its Web site information to encourage diesel-vehicle users to monitor their vehicles daily and have them inspected regularly.

To access that information (available in Japanese only), please visit us at: www.jama.or.jp/user/s10ppm/index.html

While low-sulfur diesel fuel may be used in all diesel vehicles, its use in older diesel models that have been on the road for a long time (such as route buses) can sometimes result in fuel leaks from the rubber sealants applied to fuel-injection pumps.Note, however, that diesel fuel’s flammability is extremely low, meaning that it cannot self-ignite.

The technical explanation for these fuel leaks is twofold:(1) Aroma components in diesel fuel act to expand the rubber sealants used in fuel-injection pumps, but low-sulfur diesel fuel contains fewer aroma components than regular diesel fuel;(2)With diesel vehicles that have been on the road for a long time, the rubber sealants may be subject to progressive heat deterioration, which causes them to harden and triggers a drop in the number of aroma components, leading, in turn, to a decline in sealant performance.

Diesel-vehicle users are urged to consult their auto dealer or other qualified entity immediately in the event of such a leak being detected during daily monitoring or regular inspection.

Diesel fuel leaks from fuel-injection pumps have been detected in a number of route buses, which have been using low-sulfur diesel fuel on a trial basis in Tokyo and other areas since 2001.Those buses had all been on the road for seven to eight years.

JAMA has also produced 8,000 posters summarizing its Web site information and aimed specifically at bus operators, to whom they have been distributed directly.