Cummins reveals next-generation X15 heavy-duty engine

Updated Jul 29, 2016
Cummins revealed its next generation X15 heavy-duty engine.Cummins revealed its next generation X15 heavy-duty engine.

Cummins revealed its next-generation X15 heavy-duty engine, which the company says exceeds U.S. Environmental Protection Agency (EPA) 2017 greenhouse gas (GHG) and fuel-efficiency standards.

The X15 Performance Series and X15 Efficiency Series offer lower fuel consumption, extended service intervals, enhanced performance and the highest quality standards across a 400 hp-to-605 hp ratings range, Cummins reports.

The new platform carries forward the best-in-class attributes of the ISX15 with the implementation of an optimized compression ratio, air handling system and cam profile, all off which are designed to increase fuel efficiency and performance capability.

“While today’s ISX15 is a highly popular engine, we are constantly searching for ways to improve our products,” said Amy Boerger, Cummins Vice President – North American Engine Business.

“So we examined every critical component and system to see how it could be upgraded or improved. That makes the X15 a reinvented platform for 2017 able to deliver the best performance and dependability in the industry.

“We are able to achieve this because of Cummins deep understanding of our customer needs, and a strong market presence that provides us with a unique degree of heavy-duty expertise.”

The X15 was introduced at the Transportation Research Center (TRC) in Ohio, with trucks out on the tracks to demonstrate how the latest 15-liter engines raise the bar in efficiency and performance while providing a rewarding driving experience.

The X15 Performance Series, rated from 485 hp to 605 hp, provides an ideal power match for heavy-haul, vocational and emergency vehicles. An upgraded high flow air-handling system gives a faster pedal response, for enhanced driveability at full payload and steep-gradient climbing.

Peak torque of up to 2050 lb-ft is delivered across a very wide engine rpm range, so less shifting is needed and less fuel is used. Equally powerful is the engine braking, with over 450 hp engine braking at just 1500 rpm and up to 600 hp at 2100 rpm.

For line-haul and regional-haul applications, Cummins reports that the X15 Efficiency Series offers an unmatched level of fuel efficiency and payload productivity, with a 400 hp-to-500 hp ratings range and no compromise to engine response, with up to 1850 lb-ft of peak torque available at 1000 rpm.

When integrated with the Cummins and Eaton SmartAdvantage Powertrain, it delivers class-leading fuel economy by precisely adjusting to grade, vehicle weight and driver input via throttle position.

“The X15 signals the arrival in 2017 of a new heavy-duty power capability to enable our customer’s success by unleashing unprecedented levels of dependable performance and fuel efficiency delivered by two segment-optimized engines that realize the full potential of our 15-liter platform,” said Brett Merritt, Cummins Executive Director – On-Highway Business.

“Over the past few years we have been delivering 2 percent better fuel economy per year, and the new X15 Efficiency Series will deliver that and more.”

The X15 Efficiency Series also incorporates ADEPT, SmartCoast and Predictive Cruise Control (PCC) functions, to gain a further 3 percent fuel economy improvement while making every driver an expert. An impressive 400-hp braking power arrives at just 1300 rpm, right when the driver needs it.

X15 in-service reliability will be fully validated by over 9 million miles of real-world driving before the start of full production in January 2017—the most extensive field-test program ever undertaken by the company.

According to Cummins, field-test drivers have reported a superior driving experience that has surpassed expectations in terms of both pulling and braking power, as well as fuel efficiency and uptime.

“We are entering an era defined by our commitment to uptime, and to achieve that, we have tested and validated more 15-liter-powered trucks than ever before, across all duty cycles, with some trucks putting in a huge amount of real-world miles,” Merritt said.

“Every component that was updated on the X15 was scrutinized from top to bottom, so that we weren’t just enhancing fuel economy or power – we were doing that while meeting or exceeding the highest standards of quality.”

Realizing Higher Engine Efficiency

The X15 features an optimized cam profile to minimize inherent parasitic loss during combustion, in essence breathing easier, and thus increasing thermal efficiency. Applied to the X15, it results in the highest compression ratio in the industry, enabled by the Cummins VGT Turbo and XPI fuel system, to improve engine response and reduce fuel consumption.

Additional engine efficiencies have also been realized by minimizing friction losses throughout the X15, including the water pump, gear train, lube system, piston and Exhaust Gas Recirculation (EGR).

Cummins reports that the big-bore advantage of the 15-liter platform allows the highest level of performance without compromising durability, and has an important influence on maintaining the highest residual value of the truck.

Lowering Cost Of Ownership

The X15 Efficiency Series will set a new benchmark in the industry for lowest cost of maintenance, anticipated to be reduced by almost half over the first 500,000 miles, compared to the 2010 engine, Cummins reports.

Oil-drain intervals for typical line-haul applications are extended up to 50,000 miles, depending on duty cycle, and will be able to extend to as much as 80,000 miles for trucks running at 6.5 mpg or higher with OilGuard—an oil analysis program to be introduced by Cummins. Fuel filter change intervals are also extended up to as much as 50,000 miles, and the crankcase breather filter is now maintenance-free.

A key design goal of the X15 was to reach a new level of uptime by reducing the number of components and simplifying systems wherever possible. A series of durability-focused upgrades were also made to components throughout the engine, including the camshaft lobes, piston cooling nozzles and air-handling system.

A design enhancement to the Cummins VGT Turbocharger brings higher dynamic efficiency, with a stronger actuator and impeller, to boost transient response and substantially improve engine braking at lower rpms.

The exhaust-mounted fuel injector has been removed and thermal control is now activated in-cylinder. A simple thermal recirculation device has been added to combat fuel waxing or gelling.

Single Module Aftertreatment

Designed by Cummins Emission Solutions, the Single Module aftertreatment is a true one-piece design that is up to 40 percent lighter and up to 60 percent smaller.

Installation advantages are matched by easier serviceability and a higher-capacity Diesel Particulate Filter (DPF), able to extend ash cleaning service to as much as 800,000 miles, depending on duty cycle. Integral to the system are the latest Cummins Diesel Exhaust Fluid (DEF) doser and a more robust compact mixer design, resulting in a more precise spray pattern, to minimize DEF consumption.

Better Connected

The value that Cummins is bringing to the trucking industry goes well beyond engine hardware. A first for the market, every X15 is factory-ready to enable Over-the-Air (OTA) engine programming and customization when connected to a telematics system.

Advanced solutions using Cummins Connected Calibrations applications will empower fleets to improve their productivity, and with solutions using Cummins Connected Tuning applications, the X15 can be adjusted and optimized over the air, for improved cost of operation without a visit to a service bay.

Already proven in thousands of trucks, Cummins reports that its Connected Diagnostics has contributed to maximizing truck uptime by accelerating service accuracy and speed, using telematics to wirelessly connect the engine to Cummins for rapid fault diagnosis.

It provides assurance for truck operations by allowing a service intervention to be scheduled when it is most convenient, or informs or guides them when immediate service is required.