Detroit Diesel DD15 Engine

Detroit Diesel put a different spin on the old idea of double turbocharging by linking the DD15's second, low-pressure turbo to the flywheel. Called turbocompounding, the concept captures extra exhaust energy to boost power and/or cut fuel use. The DD15 got Blue Tec exhaust-fluid aftertreatment that works with the existing particulate filter, existing exhaust-gas recirculation, and high-efficiency combustion to cut NOx emissions. The 2010 version also gets up to 5 percent better fuel economy, the company says. The 14.8-liter DD15 has ratings of 455 to 560 horsepower and 1,550 to 1,850 lbs.-ft., and is offered in Class 8 Freightliner and Western Star trucks.