American engine maker Cummins unveiled two new heavy-duty power plants for 2017, the X15 Performance and X15 Efficiency, as well as plans to roll out an X12 in 2018.

Cummins Australia has provided clarification that the X15 will not replace the 15 Litre ISXe5 in Australia as previously reported. X15 uses both EGR and SCR for emissions compliance, while the ISXe5 is a Euro 5 compliant engine using only SCR for emissions reduction.

Transport & Trucking Australia also stated the X12 would supersede the 12 Litre ISG12, which Cummins has also clarified is not the case for the Australian market, with the ISG is currently under test here and uses only SCR for Euro 5 compliance. The X12 for the North American market has both EGR and SCR.

According to president of engine business at Cummins Srikanth Padmanbhan, the new range reflects the demands of the market.

“Inspired by our customers and their business needs, Cummins is delivering the power of great ideas with our next-generation engines revealed today as the X15 Performance Series, the X15 Efficiency Series and the X12 focused on productivity, each optimised for specific duty cycles and applications,” Padmanabhan said.

“Our technology success achieves an unprecedented degree of integration across the powertrain and with the driver as represented by the Cummins and Eaton SmartAdvantage Powertrain, enabling major fuel savings by precisely adjusting to grade, vehicle weight and throttle position.”

The X15 efficiency is aimed at line-haul and regional use and is rated from 400-500hp, while the Performance variant is ideal for heavy haulage with a rating of 485-605hp. Both motors feature an optimised compression ratio, air handling system and cam profile to improve throttle response.

Cummins’ new X12 boasts the best power-to-weight ratio of any heavy duty engine produced in the USA with 350-475hp.

The X series engines also introduce a single module after treatment, which Cummins claims is 60 per cent smaller and 40 per cent lighter than modular systems, and a service life of 1.2 million km.