Navistar has launched its International S13 Integrated Powertrain for the vocational market, offering it in the International HX Series.

First introduced for the on-highway market last August in the International LT and RH Series models, the S13 Integrated Powertrain consists of three distinct components — an engine, a transmission, and an aftertreatment system — designed and developed concurrently to ensure maximum integration.

“The S13 Integrated Powertrain is the most advanced powertrain we've ever produced and the lightest vocational powertrain available on the market,” said Mark Stasell, vice president, Vocational Truck Business, in a statement. He also touted the benefits of performance, simplicity, serviceability, and operating economy.

The powertrain maximizes performance and capitalizes on efficiency made possible through its modular design in global collaboration with Navistar parent company the Traton Group.

More Fuel Efficiency, Fewer Regens

The 13L International S13 engine achieves advanced fuel efficiency and performance through a clean-burn combustion strategy and a reduction of friction and pumping losses, according to Navistar.

The S13 engine is Navistar's first engine designed with selective catalytic reduction (SCR) technology as the primary emissions reduction technology. The absence of an exhaust gas recirculation (EGR) cooler on this engine allows for nearly 100% of exhaust to flow to the fixed-geometry turbocharger, equating to more power and improved engine performance. Additionally, the engine operates on low revolutions and high torque, which equates to fewer fuel injections and less fuel consumption, delivering up to 515 hp and 1,850 lb-ft of torque.

The compact design of the Dual Stage Aftertreatment provides easy access for serviceability, as well as significantly improved emissions control and fuel efficiency. To keep temperatures at an optimal range and extend service intervals, the aftertreatment system includes a dual-stage SCR catalyst system in a one-box design.

Since an EGR cooler was eliminated from the combustion process, less soot and particulate matter are generated. This cleaner combustion cycle allows for extended service intervals and eliminates the need for the diesel oxidation catalyst (DOC) and active regeneration.

“Vocational trucks often spend quite a bit of time idling on a job site, which has historically required more frequent active regens,” Stasell explained. “The aftertreatment system of the S13 Integrated Powertrain, combined with the engine combustion strategy, vastly reduces the need for both active and parked regens.”

Transmission, PTO Options For Vocational Customer Needs

The International T14 Transmission, a 14-speed automated manual transmission, combines the transmission’s low range and six reverse gears through the use of a planetary gear set.

The T14 combines two deep crawler gears and a wide 26.7 overall ratio to provide slow-speed maneuverability, exceptional startability and enhanced performance running to and from the job site, said Navistar.

Vocational-specific drive modes include off-road mode, manual mode and paver mode. These drive modes are enhanced with other vocationally focused functionalities, such as split-shaft mode and rocking mode (which breaks the truck free when stuck.)

Shifting logic and integrated software controls maximize efficiency and performance, resulting in gear shifting that is perfectly matched to engine revolutions. The T14 also uses an electronic clutch actuator with controls integrated with the engine to deliver faster, smoother shifting.

Multiple spec'ing options are available for various vocational customer applications, including front-engine power take-off (FEPTO), rear-engine power take-off (REPTO) as well as single and dual output transmission PTOs.

All PTO options are factory-installed at Navistar's Integrated Powertrain Plant in Huntsville, Alabama, and carry the warranty of the T14 transmission.

The S13 Integrated Powertrain also takes advantage of Navistar’s Diamond Logic electrical system to optimize body integration, convenience and safety features. This provides both chassis upfitters and customers maximum flexibility, simplicity, and functionality.

Warranties and Services

The International S13 Integrated Powertrain includes several customer benefits outside of the product itself, including dealer integrated software, built-in service products and repair maintenance contracts.

Navistar's connected solution, OnCommand Connection, comes standard on all International vehicles, including those equipped with the S13 Integrated Powertrain. Combined with International 360, OnCommand Connection provides fleet monitoring and preventive maintenance scheduling to increase uptime. The OCC Go mobile app allows fleets to monitor their vehicles in real time.

When spec'd for vocational applications, the S13 Engine and Dual Stage Aftertreatment system comes standard with a two-year, unlimited miles and unlimited hours warranty, and the T14 Transmission and factory-installed PTOs feature a three-year, unlimited miles warranty. A selection of additional warranties and extended service contracts are also available.