In 2015 Volkswagen took its brands Scania, MAN, and Volkswagen Truck & Bus, and created TRATON SE, one of the world’s leading commercial vehicle manufacturers. Shortly thereafter they purchased a share in Navistar. In November of 2020 they completed the purchase giving them a foothold of the North and Central American markets. To be sure Scania, a global power in the commercial truck business, is the driving force in the group. Their quality standards and engineering prowess is leading the group forward. A little over five years ago Traton assembled a team of exceptionally talented engineers from Scania, MAN, Navistar and Volkswagen Commercial. The engineers were given a goal to design the most efficient and cleanest diesel drivetrain that would meet various stringent emission levels worldwide. The engine may be the first and last diesel designed and produced by Traton. It is to be the bridge to a future of zero emission motors. What they developed may very well change the industry. The drivetrain consists of three components, the S13 engine, the T14 transmission, and the aftertreatment system. For more than a decade, diesel engine manufacturers worldwide have in part met emission standards with designs using Exhaust Gas Recirculation (EGR), Selective Catalytic Reduction, and a particulate trap. These engines create lower NOX but a fair amount of soot. The soot, which is a function of incomplete combustion, is the cause for most of the problems that all diesel engine manufacturers have struggled with since 2010. If you talk to any diesel technician, they will tell you EGR and the soot it creates is the root cause of many of the breakdowns with current engines. Owners will tell you the systems are expensive and complex. The S13 is a new, innovative diesel engine design. First, the engineers concentrated on a design that would, to the greatest degree possible, completely burn the fuel. To accomplish that goal, they raised the compression ratio to 23:1, added dual overhead cams with four valves per cylinder to improve air intake and exhaust. They eliminated the EGR cooler because the design does not need it. They went with a fixed geometry turbocharger instead of the more complex variable geometry. The injection pressure was lowered from 36,000 psi to 26,000 psi. The Compacted Graphite Iron block is strong and light. The crankshaft, connecting rods and CGI cylinder head are all designed for the higher compression ratio. This process squeezes maximum power out of the fuel and leaves almost no soot in the exhaust, just a small amount of fine ash. What little ash produced is trapped in the DPF. Due to the small amounts of ash being produced, the engine does not have nor need a Diesel Oxidation Catalyst. All regens are passive. Due to the reduced amount of soot, the aftertreatment has much longer service intervals. One technician said, “they designed an engine to be an engine, what a novel approach.”  The S13 internal combustion process does produce more NOX than the conventional diesel of today. To manage the NOX, the engine uses a dual injection of DEF. The first injection of DEF occurs just after the turbocharger and the second in the aftertreatment container that contains the Diesel Particulate Filter. You may wonder how much more DEF the S13 will use? Current diesels use a ratio of about 4% of DEF per one gallon of diesel fuel burned. The S13 DEF usage is estimated somewhere around 4.8% to 6%. Understand that all diesels will require a higher ratio of DEF as the NOX emission standards tighten. There are many benefits to this new engine design: Improved Fuel Economy Up to 15%! Reduced Components, no EGR Cooler, no DOC, and no Variable Geometry Turbo. Reduced Complexity. Reduced Weight, it is the lowest weight of any 13L drivetrain. Lower cost of ownership. You may be wondering why the other engine manufacturers have not moved to this type of design. The simple answer is that it requires an entirely new engine design and that costs a great deal of money and time. Reports are that Traton spent five years and north of a Billion dollars developing the S13. Managing the internal pressure created by a 23:1 compression ratio must be designed in; it is not something you could modify an engine to handle. Back in 2010 none of the manufacturers wanted to engineer and build a completely new engine. It was cheaper to just add an EGR cooler and DEF. We all know how that has worked out. The secret sauce of the combo is the T14 Transmission. This fourteen speed transmission is a single countershaft design with fewer bearings, fewer gears, and less weight than its competitors. There are also multiple reverse gears. The integrated oil cooler keeps everything cool, and the wide ratio set allows for improved startability even with fast axle ratios (i.e., 2.15, 2.26 or 2.28). The T14, a 14 speed transmission has a total ratio of 26.7. Compare that to the 20.46 of the 18 speed Endurant. Startability measures the grade a vehicle will start up at clutch engagement. The first gear ratio in a T14 is 20.81 again, compared to the 14.32 in the Endurant. The ratios of the T14 make a dramatic difference in getting the truck moving and keeping drivers happy. Other shift strategies assisting the driver are based on load, accelerator position and other inputs. The transmission will choose the best gear necessary to start and then to keep the truck operating as efficiently as possible as it goes down the road. The electronic clutch actuator allows for precise and fast movement of the clutch. The benefit is fast, smooth shifts. It is serviceable in-chassis. This is critical to improving shift strategies between the engine and transmission. The best way to really understand how good this new engine, transmission and aftertreatment combo perform will be to drive it. We are excited to offer extended test drives for this exciting new product. Two tractors are available, a new LT Day Cab and a new LT Sky Rise Sleeper. If you would like more information or want to be one of the first to experience the drivability and fuel efficiency of the new S13 Integrated drivetrain, reach out to us now so we can get you on the schedule! © Dayton Shepard and Michael Olden 2024