Issue link: https://read.dmtmag.com/i/82527
ENGINE INNOVATION is preparing to launch its next gen- eration of heavy-duty diesel engines. Overdrive was lucky enough to get one of the first test drives of these new engine families. The new ISX15 will appear in new trucks early next year. The engine is amazingly smooth and surprisingly quiet. Because it's a smart engine, you might have to break a habit or two in terms of shifting patterns or gear selection in order to get the most out of it. But Cummins has designed it in a way that it coaches drivers to get the best fuel economy possible while deliv- ering plenty of power – all the while making the driver safer and more pro- ductive. Lou Wenzler, on-highway commu- nications director, says that Cummins today is all about boosting fuel econo- my in its engine designs, with targeted improvements of up to 2 percent over its current engines. Since the engines burn less fuel, the improvements allow the new ISX15 to already meet 2014 Federal Greenhouse Gas Emissions regulations. "We're also going to offer better performance from these next-genera- tion engines," Wenzler notes. "Drivers will notice improved response to their throttle inputs along with taller gear- ing and 'smarter' electronics that will allow them to drive better by helping manage power demands while still delivering improved fuel economy." The ISX15 I'm driving on this crisp June day is a prototype engine mounted in a 2012 Peterbilt 386 that Cummins keeps at its product evalua- tion lab on the outskirts of Columbus, about an hour south of Indy off I-65. The engine churns out an impres- sive 450 horsepower while running at 1,750 rpm. Cummins plans three versions of the ISX15, based on torque and horsepower. This test engine, what Cummins calls a Family One, will be introduced for fleets next year. A Family Two version for owner-opera- 42 | Overdrive | October 2012 The new ISX15 is a "smarter" engine, which means more electronically controlled driver enhancement features than seen on previous Cummins engines. Tractor: 2012 Peterbilt 386 Engine: ISX15 Family 1 tor and premium fleet trucks, as well as a 600-hp Family Three variant for heavy haul, will follow soon afterward. To help boost fuel economy, Wenzler says, engineers worked hard to reduce parasitic loads inside the engine design, including a new, opti- mized fuel pump with reduced inter- nal friction, a newly designed variable geometry turbocharger and a new intake throttle design to optimize EGR flow in the engine. "We're looking at every detail, no matter how small," Wenzler adds. "For example, how fast do you need to spin a water pump to maintain cooling effi- ciency? And how does that affect fuel economy? Nothing is off the table." Cummins has also taken advantage Transmission: Eaton-Fuller RTLO- 16913A 13-speed manual Axle: Dana 3.08 GVW: 75,000 pounds of more powerful electronic engine controls to make drivers' lives more comfortable during long days behind the wheel. To that end, the new ISX15 will feature multiple new driving tools. One major one is a new gearing sys- tem, says Jason Owens, customer per- formance technical manager. He's the guy who teaches Cummins customers how to drive these new engines for optimum efficiency. For most drivers, ISX15 SPECS AS TESTED Power rating: 450 horsepower at 1,750 rpm Gearing: 1,235 at 65 mph