JAPAN: Latest Mazda diesel meets new metropolitan region emission laws
Source: just-auto.com editorial team
Mazda’s restyled Bongo van and truck range includes a newly developed diesel engine claimed to be the first in their class to comply with Japan's new Short-term Diesel Emissions Regulations and the Automobile NOx/PM Control Law, making them eligible for sale and registration in the major metropolitan areas of Tokyo, Osaka and Nagoya.
Performance and fuel economy are claimed to be significantly improvement over the previous diesel engines used in the Bongo series.
The new two-litre in-line four cylinder, common-rail direct injection turbo diesel engine employs technology that greatly reduces the amount of particulate matter and nitrogen oxides in exhaust gas emissions. Based on the MZR-CD engine used in the European specification 6 range, the engine is equipped with a new diesel particulate filter and an improved engine control unit. As a result, PM emissions have been reduced by more than 75%, while NOx emissions have been cut by 25% compared to the 2.2-liter diesel previously used.
The engine employs a diesel particulate filter coated with an oxidation catalyst. The ceramic filter traps PM, and when the amount of PM in the filter reaches a designated level, it is automatically removed through the combined effect of the catalyst and combustion temperature controlled by the common-rail injection system.
NOx emissions are reduced further by optimally controlling the combustion temperature with "Cooled EGR" and by improving combustion efficiency with fuel injected at high pressure from the common-rail.
Common-rail direct injection system with precision-controlled fuel injection pressure and injection timing along with a small, high efficiency turbocharger greatly improve vehicle performance compared to the previous diesel engine. Maximum output has been increased from 58kW (79 PS)/4,250 rpm to 63kW (86PS)/3,500 rpm. Maximum torque has also been enhanced by around 30% from 138Nm (14.1 kg/m)/2,000 rpm to 178Nm (18.2 kg/m)/2,000 rpm.
The new two-litre diesel engine achieves 15.4 km/l compared to the previous 2.2-litre diesel engine's 13.6 km/l.