Cummins launches ‘new era’ truck diesels

Cummins Inc. has announced what it calls a “new era” in heavy-duty power with the next-generation X Series. With the line-up expanded to three X engines, the ratings extend from 350 bhp to 605 bhp.

Cummins says this “represents the broadest and most capable heavy-duty engine range that Cummins has ever made available to the North American truck market”. The range comprises the 15-litre and 12-litre truck diesel engines.

“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 optimized for specific duty cycles and applications,” commented Srikanth Padmanabhan, Cummins president – engine business.

Cummins claims its X engine platform “builds on the success of the current heavy-duty engines, taking on new names to reflect the evolution and introduction of the product platforms to meet Phase 1 greenhouse gas (GHG) and fuel-efficiency standards, to be fully implemented in 2017.”

The company adds that “by taking highly innovative approaches, combined with a series of finely tuned improvements on existing technologies, the X15 brings unmatched performance and fuel efficiency, with the implementation of an optimized compression ratio, air handling system and cam profile.”

Cummins also claims the X12 “redefines the meaning of medium-bore power with by far the highest power-to-weight ratio of any heavy-duty engine.”

It adds that all three engines are “integrated with the revolutionary Single Module after-treatment. Up to 60 per cent smaller and 40 per cent lighter than modular after-treatment systems, the Single Module is capable of taking DPF ash cleaning events to as much as 800,000 miles on the X15.”

All three engines will be manufactured at the Cummins Jamestown Engine Plant.                                      Best-in-class attributes

The X15 Performance Series, rated at 485 bhp to 605 bhp, has a peak torque of up to 2,050 lbft.

The X15 for Stage V applications will retain the same DPF-SCR after-treatment system in order to provide ongoing installation continuity for OEMs in higher-output, more specialised machines. The EGR-free X15 lowers heat rejection by over 40 per cent compared with that of engines using cooled EGR.  The X15 carries forward to Stage V certification with no modification required to the existing engine architecture – leading the way for other Stage V designs.

The 12-litre engine is rated up to 475 bhp, and provides up to 1700 lbft peak torque at 1,000 rev/min, which remains available to over 1400 rev/min.

Cummins claims the “innovative architecture of the X12 results in a remarkably low engine weight – 2,050 lb – enabled by a sculptured block design, which allows unnecessary mass to be removed, but retains high rigidity”.

Substantial weight savings are also achieved by the use of high-strength composite materials for the oil pan and valve cover.

Interestingly, Cummins has chosen not to use compacted graphite iron (CGI) as the cylinder block material to achieve even further gains in weight-saving – a material it uses for the vee block of the ISV5.0.

Notwithstanding this the company claims it has examined every avenue for advancement.

“During the design process for the X12, we evaluated every opportunity to reduce size and lower weight, but importantly, we achieved this with no compromise to structural strength, so that our next-generation 12-litre comes with all the durability associated with a Cummins Heavy-Duty engine,” commented Jim Fier, Cummins vice president – engineering.

The next-generation X12 will be built at the Cummins Jamestown Engine Plant alongside the latest X15 Efficiency Series and X15 Performance Series.