Cummins Inc has submitted its 5.9-liter ISB engine to the Environmental Protection Agency (EPA) for certification to the 2.5-gram NOx+NMHC standard. Production will begin upon receipt of certification, expected in early summer 2002.
To meet the EPA emissions standard, a cooled exhaust gas recirculation (EGR) subsystem was added. Including base engine experience in Europe, the ISB with the cooled EGR subsystem will have more than one million field test miles by time of production. Designed for medium-duty trucks, step vans, and buses, the ISB has new features including:
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High-pressure common rail fuel system — with multiple-injection capability for improved performance, lower emissions, and reduced noise.
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Variable Geometry Turbocharging (VGT) — on ratings of 245 hp and above, the VGT offers reliability and durability.
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Rear gear train — with cam, fuel pump, and accessory drives in the rear of the engine for increased accessory drive capability and less noise.
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Cooled EGR — which reduces exhaust gas temperatures before reintroducing it back into the combustion chamber.
The ISB offers horsepower ratings from 185 to 275 and torque from 420 to 660 ft-lb. It improves fuel economy as much as 2% with 15,000-mile oil change intervals still standard. Furthermore, this ISB is up to 80% quieter than its predecessor.