Navistar has started full series production on the new International S13 integrated powertrain at the company’s Huntsville, Alabama, plant — the last internal combustion engine the company will ever produce.

A ceremonial ribbon-cutting opened the new, highly automated assembly line Oct. 18 as plant workers, Navistar and Traton executives, and state and local dignitaries watche.

The dedication of the new powertrain was poignant, however, and in many ways marks the end of an era for Navistar. That’s because the International S13 integrated powertrain — composed of the S13 engine, T14 transmission, and dual stage aftertreatment system — marks the final combustion product platform that Navistar will develop as the company transitions toward zero-emissions vehicles, said Stefan Palmgren, executive vice president, production and logistics, Navistar.

“We at Navistar are on a journey to accelerate the impact of sustainability with zero-emission solutions that support the future growth of our customers,” he said. “This internal combustion engine is an important milestone on that journey. Our S13 powertrain and ICE technology today provides a balance for our customers by providing them with a cleaner, yet more affordable propulsion technology to use while zero-emission technologies build out.”

Navistar — then International Harvester — designed and built its first proprietary internal combustion engine in 1907. Which means that when A26 engine production finally ceases, most likely some time in the next decade, will mark the end of over a century of reliance on ICE technology for the long-lived truck OEM.

Sustainable Plant Building Sustainable Powertrains

Navistar recently completed a 110,000-sq.-ft. expansion of the Huntsville Powertrain Plant to support the production of the new S13 integrated powertrain components. With the addition, the now 410,000-sq.-ft. facility has transitioned from a single assembly line to two — one for the T14 transmission and one for the S13 engine — along with the incorporation of three major machining lines.

These improvements mark the first time the Huntsville plant will produce a transmission.

Overall, Navistar has invested more than $200 million in the Huntsville plant, which was established in 2008 and employs more than 230 skilled workers in the area.

"Through collaborative efforts with the Traton Group, we are confident to set a new efficiency benchmark in sustainable transportation,” said Brandon Tucker, director of operations, Huntsville Powertrain Plant. “The entire team is excited to embark on this journey and build the remarkable S13 integrated powertrain that will redefine the industry and power our path towards a more sustainable future."

In addition to the new assembly and machining lines, sustainability improvements were made to the plant. Those include LED lighting, a wastewater evaporator to minimize wastewater discharge, and new augers to separate recyclables from rubbish to significantly reduce the waste to landfill.

The expansion began back in February 2020 and has added roughly 100 jobs to the plant. In addition, many key manufacturing process improvements have been installed, such as robotic assembly cells, enterprise connected manufacturing devices with advanced error proofing, and automated guided vehicles that allow the plant flexibility when needed.

“When you add the manufacturing technology with our skilled employees, we’re producing the highest quality product possible in an extremely efficient process for all of our customers,” added Tucker.

Boost in Fuel Economy

Announced in August 2022, the S13 integrated powertrain, developed in collaboration with Navistar parent company Traton, significantly increases operating efficiency, reduces operating costs, and provides greater profitability for customers, according to the company.

Ryan Ludera, S13 program manager for Navistar, explained that the 13-liter engine achieves advanced fuel efficiency and performance through combustion efficiency and a reduction of friction and pumping losses.

The dual-stage aftertreatment system saves fleets time and enhances fuel economy. Eliminating the exhaust gas recirculation ensures a more complete fuel burn and allows cleaner air to enter the combustion chamber on the intake cycle to mitigate soot buildup.

“This was a clean-sheet design that resulted from a partnership between Traton, Scania and Navistar,” Ludera explained. “These groups all stood up to figure out how to develop this powertrain a global platform, but still allow it to be tailored to meet North American fleet needs.”

“A modular design allowed us faster time to market while improving quality and reliability,” Palmgren added. “This also allows for regional adaptation to address specific customer needs around the world.”

Building on that point, Palmgren noted that the Huntsville launch is actually the third introduction for the S13 powertrain. Scania introduced it in Europe in 2021. It debuted in Brazil last year. The S13 will also be released in China in the near future.

Ludera called the S13 powertrain the most efficient that Navistar has ever designed and built and noted that the T14 automated transmission is engineered specifically to work with the S13 powertrain.

“We are focused on efficiency with this engine and now this integrated powertrain,” he said. “With the S13 powertrain, we can give fleets longer service intervals and a tremendous improvement in fuel economy. The S13 powertrain delivers 15% better fuel economy than a non-integrated powertrain. All off this gives our customers lower total cost of ownership as well as sustainability.”

The S13 goes into production in Huntsville with thousands of hours of research and development work behind it, as well as millions of road-test miles and extensive climate testing to validate its performance. Ludera said “the keys will soon be in customer hands,” and that he is excited about seeing the powertrain finally getting fleet service.

“The S13 powertrain is a very strong contribution by Navistar on our road to sustainability,” Palmgren added. “Eventually, Navistar will be a producer of 100% zero-emission vehicles. But in the meantime, this powertrain will give our fleets a fuel-efficient option that shows that great opportunities for both Navistar and our customers lie ahead.”