The Japanese government has finally capitulated to foreign pressure, or gaiatsu, and Tuesday announced it is revising regulations on allowable vehicle exhaust emissions. The new rules are to take effect in the autumn of 2000. When the current standard on pollutant emissions was established in 1978, it was the strongest set of regulations in the world. But manufacturers and regulators in the United States and elsewhere have been pushing strongly to reduce pollutants, making Japan's standard look outdated.