Cummins announces X15 and X12 engines

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Cummins engines gallery 1 Cummins will begin production of the new engines in 2017.
Cummins X15 A look at the new Cummins X15 engine

New heavy-duty engines will hit the US in the coming years.

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Engine manufacturer Cummins Inc has launched two new models for the US market this week, unveiling the heavy-duty X15 and X12 engines.

Both the X15, which is effectively a rebranded and upgraded version of the current 15-litre ISXe5 engine used in Australia, and the X12, which is the new name for the ISG12 12-litre engine that has been trialled in Australia for some time, are currently scheduled to hit the US market in 2017 and 2018, respectively.

Cummins says the next-generation X15 engine boasts emissions, fuel efficiency and consumption, service interval, and performance gains and will ship in two configurations – the X15 Performance Series and the X15 Efficiency Series.

The Performance Series (above, right), rated at 485hp to 605hp, is aimed at heavy-haul, vocational, and emergency vehicles.

Cummins says it provides faster pedal response thanks to an upgraded high flow air-handling system, it has a peak torque of up to 2050 lb-ft "across a very wide engine rpm range", and has "over 450hp engine braking at just 1,500rpm and up to 600hp at 2,100rpm."

The Efficiency Series (right), rated at 400hp to 500hp, is aimed at line-haul and regional-haul applications.

As the name suggests, Cummins says it provides "an unmatched level of fuel efficiency and payload productivity … with up to 1,850 lb-ft of peak torque available at 1,000rpm."

The economic-focused range also features DEPT, SmartCoast, and Predictive Cruise Control (PCC) functions, which Cummins says, offer a 3 per cent fuel economy improvement.

Across both models is a redesigned cam profile, a greater focus on over-the-air connectivity and data retrieval, and oil-drain intervals extended out to 50,000 miles (80,500km) or, in some cases, 80,000 miles (128,700km).  

The X15 range also takes advantage of the company’s new Single Module aftertreatment, which is 40 per cent lighter and up to 60 per cent smaller than current aftertreatment designs.

Cummins executive director of on-highway business Brett Merritt says the company is "unleashing unprecedented levels of dependable performance and fuel efficiency delivered by two segment-optimised engines that realise the full potential of our 15-litre platform."

"Over the past few years we have been delivering 2 per cent better fuel economy per year, and the new X15 Efficiency Series will deliver that and more," he says.

Both models will undergo a 9 million mile (14.5 million km) test before production begins in January 2017.


The smaller of the two new engine ranges is the X12 Series (right), a 12-litre engine targeted at regional-haul, intracity delivery, and vocational trucks.

Rated up to 475hp and providing up to 1,700 lb-ft peak torque at 1,000rpm, Cummins says the X12 has "the highest power-to-weight ratio of any engine in the 10-to-16-litre class".

Weighing 930kg, the new engine has a sculptured block design and features high-strength composite materials for the oil pan and valve cover.

"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,"  Cummins vice president of engineering Jim Fier says.

It’s "an ideal fit for shorter-nose conventional cabs," he says, and the "very low weight makes the engine a great power solution for sleeper trucks sensitive to front axle weight."

For specific restricted applications, Cummins says a higher 500hp rating will also be available.

Like the X15, the X12 Series will utilise over-the-air connectivity, the new aftertreatment design, and incorporate Cummins ADEPT, SmartCoast, and PCC technology.

The X12 will be available in 2018 after its own test period.

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