As the International S13 powertrain rolls out to customers, the OEM also rolled its new engine, transmission and aftertreatment package out to TMC, held earlier this month in New Orleans. David Crowe, S13 integrated sales manager at International Trucks, walked us around the powertrain that is characterized by its dual overhead cam engine design, which aims to improve combustion efficiency by increasing the compression ratio. This approach reduces the need for complex components, such as the EGR cooler, which has been eliminated.
“When you look at what an EGR cooler is doing, it’s all about trying to control your levels of NOx being produced in that combustion process. What you’re actually doing is you’re introducing roughly 20% dirty air back into the cylinder—things like carbon and soot that gunk up the inside of the engine—and also sending all of that waste downstream,” Crowe explained. “By eliminating that, you clean everything up and you’re eliminating those failure points for fleets.”
The engine’s design also simplifies the system by lowering fuel pump pressure and employing a fixed geometry turbo instead of a variable geometry turbo. Crowe also noted that by achieving a more complete burn of diesel fuel, emissions of soot are reduced, and NOx emissions are managed through an advanced aftertreatment process.
Speaking of the aftertreatment system, the S13’s one-box aftertreatment is designed to handle NOx emissions with a dual dosing of diesel exhaust fluid (DEF). The system also removes the diesel oxidation catalyst (DOC), simplifying the exhaust treatment process and eliminating the need for fuel consumption for regeneration.
“We go back to the aftertreatment being part of a system, and since we cleaned the burn combustion with higher compression, we have a super high level of NOx—that’s the magic ingredient that allows us to eliminate the DOC,” Crowe said. “We’re changing the chemistry where soot converts to ash. Rather than seeing in conventional diesel systems where you need 500 or 600 degrees Celsius, you can actually get that soot to convert to ash at around 300 degrees Celsius.”
Then there’s the brains of the S13 powertrain operation: the T14 transmission, offering 14 speeds and a broad ratio coverage for efficient operation under various conditions. The transmission supports a weight rating up to 242,000 lbs. for highway applications and incorporates intelligent shift optimization to improve fuel efficiency and user experience.
“Integrating in with our engine with our transmission allows us to not only integrated our optimized shift strategies in the transmission for either Economy Performance or Performance Plus, but we’re now able to integrate our predictive cruise control and adaptive cruise control functionality to deliver a better experience,” Crowe said. “One thing that this system does extremely well is it manages your speed for predictive cruise control exceptionally, and that’s where you’re going to get the best fuel economy is by utilizing your cruise control.”
There are plenty more S13 powertrain specs to talk through. Watch the video above for all of the horsepowered details.
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