Nevada’s Las Vegas Motor Speedway was the site of one of the biggest unveilings in heavy-duty trucking – the Navistar S13 Diesel. Current trends indicate the gradual retirement of internal combustion engines in favor of electric drivetrains.
Top executives at Navistar and other world leaders such as Scania, Volkswagen Truck, Traton, and Germany’s MAN expect this to be one of the last internal combustion powertrains we’ll ever see developed from the ground up. And it certainly is an impressive final curtain.
The S13 Integrated Powertrain has a fuel-efficient 12.7-liter diesel engine designed to be at the cutting edge of efficiency, ruggedness, innovation, and power.
The S13’s Superlative Efficiency
The S13 aims to overthrow Navistar’s previous flagship, the A26 Diesel, introduced five years ago. This 400-horsepower, 2,284-pound diesel will achieve significantly better fuel economy than its older sister. The engine has been carefully developed by a conglomerate of engineering luminaries to be as easily serviced and repaired as possible. It features a low-pressure oil pump, double overhead cams, a fixed geometry turbocharger, and a 23:1 compression ratio – all contributing to its impressive efficiency.Quiet yet Robust T14 Automated Transmission
Explaining the virtues of the S13, Navistar’s Michael Grahe explained that the truck is rugged enough to last a million miles of service. The self-shifting T14 transmission system seems, by all accounts, to be more than capable of delivering the trinity of quiet, smooth, durable performance. Whether you opt for the sleeper-cab or regular-cab version, the S13’s T14 transmission features dual creeper gears with close ratios running up to 13th gear in direct drive and tipping into overdrive in 14th gear. 14th-overdrive is programmed to kick in when the truck is headed downhill or carrying a light load, but the most outstanding fuel economy will be experienced when the truck is loaded and running in 13th-direct gear. To keep things running smoothly under all conditions, you’ll have an additional 469 retarding horsepower thanks to the compression engine brake that comes as standard with the truck.Next-Generation Aftertreatment System
If you’re concerned with keeping your carbon footprint low and your environment pristine, as you should be, then you’ll be happy with the S13. It comes fitted with an excellent after-treatment system that utilizes a two-stage exhaust fluid dosing system. The first stage takes place adjacent to the turbo unit, while the second stage occurs in the box container that doubles up as the housing for the diesel particulate filter. To top all this off, the S13 does not need any active regenerations to be effective, although they retain actuation capabilities should it be necessary. This is a significant step up from previous generations of trucks and long-distance haulers.Rating Options
The S13 diesel is in high demand, as illustrated by the plethora of ratings in which it will be rolled out. Expect ratings ranging from the 370 horsepower, 1,250 pound-per-foot torqued models to the 515 horsepower, 1,850lb-ft iteration. The highest fuel economy will likely be seen in the 400-horsepower version, which might see up to a 15% efficiency improvement.Final Thoughts
Navistar is pinning much hope on the S13’s global performance, so they have conducted extensive testing in extreme climates. It has been taken through 4 million miles of terrain ranging from Alaska to Arizona and has successfully undergone more than 400,000 road hours of dynamometer testing. According to Navistar Director David Hillman, Navistar intends what looks to be its best and last internal combustion engine and transmission at its newly expanded factory located in Huntsville, Alabama.
