Cummins launches three next-generation X-series engines

July 27, 2016
Find 2017 compliant Cummins engines X12 and X15 with plenty of power and low fuel consumption.

Tank truck fleet managers and drivers should find plenty to like with three all-new 2017-compliant engines that were unveiled recently by Cummins Inc. Key features include plenty of power, lower fuel consumption, extended service levels, noticeably less engine noise, and new single-module aftertreatment system that frees up frame rail space.

The three next-generation X-series engines (replacing the ISX-series) were introduced during a media event at the 4,500-acre Transportation Research Center south of Columbus OH. The big-bore X15 Performance and X15 Efficiency and the medium-bore X12 were put through their paces on the research center’s 7.2-mile test track. The X15 engines will be in production before the end of this year, and the X12 will be available in 2018 after completing an extensive field-test program.

The X15 Performance Series, rated at 485 horsepower to 605 horsepower, provides an ideal power match for heavy-haul, vocational, and emergency vehicles. Target customers include tank truck fleets running longhaul operations and those operating equipment with higher gross combination weights.

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 1,500 rpm and up to 600 hp at 2,100 rpm.

For linehaul and regional-haul applications, 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 1,000 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.

"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 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% better fuel economy per year, and the new X15 Efficiency Series will deliver that and more"

The 12-liter X12 is rated up to 475 hp, and provides up to 1,700 lb-ft peak torque at 1000 rpm, which remains available to over 1,400 rpm, reducing the need for gear shifting and giving better low-speed lugging on grades. The innovative architecture of the X12 results in a remarkably low engine weight--just 2,050 pounds--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.

"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-liter comes with all the durability associated with a Cummins Heavy-Duty engine," said Jim Fier, Cummins vice-president-engineering, during a drive on the 7.2 mile TRC oval track.  

"We are really excited about how the next-generation X12 will complement our engine portfolio and provide to our OEM partners a compact yet capable engine--an ideal fit for shorter-nose conventional cabs--while very low weight makes the engine a great power solution for sleeper trucks sensitive to front axle weight."

The X15 and X12 engines incorporate Cummins ADEPT, SmartCoast, and Predictive Cruise Control (PCC) functions, to gain a further 3% fuel economy improvement while making every driver an expert. An impressive 400-hp braking power arrives at just 1,300 rpm, right when the driver needs it.

X15 in-service reliability will be fully validated by over nine 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. 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."

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). 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.

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. 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.

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

In 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 X-series engines can be adjusted and optimized over the air, for improved cost of operation without a visit to a service bay.