“Future GHG regulations are requiring dramatic reductions in aerodynamic drag, along with more efficient engines,” Moore said. He believes future advances in horsepower and torque will allow these smaller engines to cross even further into their larger-displacement counterparts’ applications zone at increased efficiency. In addition to technology advancements, helping to drive this trend toward smaller engines are increasing federal emissions regulations, Moore said. ”You can post excellent miles-per-gallon numbers, if set up correctly.” “The fuel maps on these engines are optimized for regional haul, less-than-truckload and diminishing-load applications running on flat to rolling hills,” Moore said. It’s largely about fuel efficiency, said John Moore, powertrain product marketing manager for Volvo Trucks, which offers a 10.8-liter D11 engine. That doesn’t mean the 15-liters went away, but a large proportion of that business has moved to 13-liters.” In the past, you would see lots of 15-liters, and then the 13-liters came in and we saw a trend into 13-liters. “The race to add more horsepower has really slowed down over the last 15 to 20 years,” he said. This is why there also are many more 13-liter engines in use today compared with 15-liter ones, said Mike Evans, senior consultant at Rhein Associates. In other words, a lot of the move to smaller engines has to do with efficiency. “Together, they sense factors like the load on the truck, incline, decline, speed and more to get the most performance and efficiency out of a smaller engine displacement.” “Our MP engines are fully integrated with mDRIVE, sharing 100% of the information 100% of the time. “Integration plays a role, too, particularly in the case of our mDRIVE automated manual transmissions,” Russoli said. ![]() Mack Trucks offers the 11-liter MP7 with 325 to 405 hp and torque ratings from 1,200 to 1,560 pound-feet, which maintains what Stu Russoli, highway and powertrain products marketing manager, calls “good efficiency numbers.” The increasing sophistication of engine control software is helping. “Similar to what we have seen in passenger cars, truck engines are adopting dual overhead cams, variable timing, high-pressure fuel systems, multistage turbocharging and sophisticated materials like compacted graphite iron on the blocks and head castings,” the latter making the engines lighter. “Increased power density is the objective, which drives adoption of aggressive compression ratios, increased injection pressures and higher fresh air induction,” he said. More technically, this means several things, said Mario Sanchez-Lara, director of on-highway marketing communications for Cummins, which makes the 11.9-liter ISX12 model engine. “We are getting 430 horsepower and 1,550 pound-feet of torque out of the new MX 11-liter engine, something that a few years ago would have required a much larger engine.” “We are able to achieve more horsepower and torque with less displacement,” he said. These engines aren’t new, but the power they deliver is much more than it was, even just a few years ago, said Charlie Cook, marketing manager for vocational products at Peterbilt, which is owned by Paccar. So what’s driving the trend toward smaller engines? Several factors. Paccar isn’t alone when it comes to having engines in and around 11 to 12 liters, with offerings in the United States from Cummins, Navistar, Volvo and Mack. The MX-11 is built at Paccar’s engine manufacturing facility in Columbus, Mississippi, along with the MX-13. The move by Paccar followed the 2013 launch of the MX-11 in Europe, where it has installed more than 10,000 of these engines in trucks made by its European operation DAF. ![]() It went into a Peterbilt Model 567 for North Dakota-based fleet Knife River, one of the largest aggregate producers and suppliers of concrete and asphalt in the United States. upped the ante by installing in the United States its first production MX-11 engine, a 10.8-liter power station. With evolving technology and additional greenhouse-gas (GHG) emissions and fuel-economy regulations pending, smaller engines are becoming more common - not just 13-liter models but also those in and around the 11- to 12-liter range. That often meant 15-liter engines that could deliver a whole lot of horsepower. ![]() Not that long ago, the mindset of many fleet operators was to get as much muscle power in engines as they wanted or could afford.
0 Comments
Leave a Reply. |