Cummins’ latest ISB engines have now been certified to Euro6, ready for January 2014 when it becomes mandatory for all newly registered buses and coaches to meet the standard. Available with outputs from 150 to 310ps, the manufacturer claims the power units are ideal for single and double deck buses and coaches. They use EGR and variable geometry turbocharging (VGT) technologies to achieve the benchmark. These are matched to the aftertreatment system, designed and produced by Cummins Emission Solutions. It combines a Diesel Particulate Filter (DPF) with SCR to meet the low emission levels. The successful certification is a result of a three year ISB Euro6 development programme. Engineers carried out over 30,000km of product validation in challenging vehicle operating conditions in Spain and Scandinavia to ensure emissions compliance. Ambient temperatures ranged between 35C and -29C during the tests, which also took the vehicles to altitudes of more than 2000m.
Chief Engineer of Product Development, Jonathan Atkinson, said, ‘Our testing has successfully validated Cummins’ hardware and control strategy for Euro6 in extreme temperatures. It has proven that the upgraded Euro6 OBD system would not generate unnecessary fault codes that could limit vehicle operation in these difficult climates. This has been an important step in our development programme, ensuring that Cummins’ Euro 6 package delivers for all vehicle users, wherever they operate. The after treatment system provided more of a challenge than at previous emissions levels, as it has to be kept within a specific temperature band to operate efficiently. This is achieved through advanced control strategies which manipulate the engine hardware and combustion strategy to maintain exhaust temperatures in the optimum range, whilst delivering the best possible fuel efficiency.’