Cummins is set to make a commanding statement at the 2025 Brisbane Truck Show with the official display of the all-new X15D engine – a high-performance, next-generation diesel engine.
Known as the PX-15 in Paccar's recently launched DAF XG cabover, the X15D is available exclusively with Euro 6 emissions compliance and introduces a new benchmark in on-highway engine performance.
"Cummins has taken internal combustion to the next level with the X15D," says Sean McLean, Director and General Manager of On-Highway Business for Cummins South Pacific.
"It delivers the highest-ever outputs for a Cummins truck engine while setting new standards for fuel efficiency at ultra-low emissions levels."
The X15D boasts a top rating of 660 hp at 1800 rpm and a peak torque of 2360 lb-ft, available across a wide band from 1400 down to 900 rpm. This supports Cummins' advanced engine downspeeding strategy—designed to reduce cruise rpm for greater fuel economy while maintaining strong performance to satisfy both drivers and operators.
Another standout feature is the engine's weight advantage. With a dry weight 225 kg lighter than the current X15, thanks to innovations like a sculpted iron block and composite oil pan, the X15D now delivers the highest power-to-weight density in the industry. For cabover applications, the reduced engine weight provides a notable benefit in lowering front axle tare.
The new engine platform also features the latest generation of Cummins' Extreme Pressure Injection (XPI) fuel system and comes equipped with a standard wastegate turbocharger. Euro 6 compliance is achieved via an integrated single module aftertreatment system that houses both the diesel particulate filter (DPF) and the AdBlue SCR unit.
The X15D has already entered the Australian market under the PX-15 name in the DAF XG cabover, paired with ZF's 16-speed automated TraXon transmission and Cummins-Meritor MT21-165 rear axles. The vehicle is rated for a gross combination mass (GCM) of 97 tonnes.
"The X15D will be available for other truck brands to meet Euro 6 requirements into the future," says McLean, noting that even higher GCM applications will be supported following further local testing and validation.
"Initial field testing of the engine has focused on B-double type applications," McLean explained.
"Eighteen units rated at 660 hp have been involved in the validation program with customers, accumulating around six million kilometres.
"The program has met our objectives and that was to gain feedback on fuel economy, performance and durability," he said. "We've had great feedback, especially on driveability and torque."
Further testing is ongoing with higher gross weight combinations to ensure the X15D continues to meet Cummins' high standards of durability and performance.
The X15D forms a core part of Cummins' HELM platform—Higher Efficiency, Lower Emissions, Multiple Fuels—which features fuel-agnostic engine technology designed to operate on diesel, natural gas, or hydrogen. All variants are derived from a common base with high parts commonality, reducing complexity and streamlining maintenance.
The X15D will be a must-see at the Cummins stand during the Brisbane Truck Show, offering a glimpse into the future of heavy-duty road transport in Australia and beyond.
Cummins will be located at stand 94 at the Brisbane Truck Show from May 15 to 18, 2025 at the Brisbane Convention and Exhibition Centre.
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Cummins Inc., a global power solutions leader, comprises five business segments – Components, Engine, Distribution, Power Systems, and Accelera by Cummins – supported by its global manufacturing and extensive service and support network, skilled workforce and vast technological expertise. Cummins is committed to its Destination Zero strategy – the company's commitment to sustainability and helping its customers successfully navigate the energy transition with its broad portfolio of products. Cummins has approximately 69,900 employees and earned $3.9 billion on sales of $34.1 billion in 2024. See how Cummins is leading the world toward a future of smarter, cleaner power at www.cummins.com
