Cummins upgrades ISB engines ahead of Euro 6 OBD deadline

[kscarbel2]

Transport Engineer / September 21, 2015

Cummins had increased the power and torque on selected versions of its latest SmartEfficiency four- and six-cylinder ISB truck and bus engines, which now conform to the latest Euro 6 On-Board Diagnostic (OBD) ‘C’ requirements.

OBD C applies to new vehicle type approvals from 1 January 2016 and all vehicles from 1 January 2017 and sees reductions in the NOx emission threshold detected by the engine’s diagnostic system, from 1,500mg/kWh to 12,000mg/kWh.

A PM (particulate matter) detection threshold of 25mg/kWh is also introduced, while the level at which sub-standard AdBlue (urea) is detected is further lowered from 0.9g/kWh to 0.46g/kWh.

Finally, the OBD C diagnostic operation must report how many times the monitor successfully runs per number of drive-cycles.

As part of the performance upgrade, peak torque on the latest OBD C 4.5-litre ISB engine is raised to 850Nm from the previous 760Nm maximum on Euro 6 OBD A versions, while peak torque on the six-cylinder ISB 6.7-litre OBD C engine moves up to 1,200Nm (1100Nm on OBD A engines).

Specifically for bus applications there is a new 300hp 6.7-litre top rating too, which is being offered as an engine ‘down-sizing’ option in preference to equivalent power nine-litre diesels.

The 300bhp ISB not only saves weight but requires a smaller packaging envelope compared with a bigger-displacement diesel.

Revisions to the ISB’s engine-mapping have also resulted in higher torque outputs being available lower down the rev range, further improving driveability and fuel economy.

Meanwhile, for truck operators the maximum power rating on the ISB six-cylinder goes up from 310 to 320bhp. Service intervals on ISB OBD C engines have also been extended beyond 2000hrs/90,000kms.

Cummins says its latest ISB four- and six-cylinder Euro 6 diesels, which will become available before the end of the year for OEM adoption in 2017, makes them ‘best-in-class’ in terms of their power/torque-to-weight ratio.

Since their introduction in the last quarter of 2013 Cummins has supplied over 18,500 Euro-6 ISB four and six-cylinder engines to truck and PSV manufacturers worldwide.

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