With more than 250,000 of the engines already in service worldwide, Mercedes-Benz has introduced the Euro VI-compliant version of the OM 471. OM 471 is the European version of North America's DD13 engine. The engine was introduced last month at a press event in Berlin, Germany.

Mercedes-Benz says the OM 471 is 3% more fuel efficient than it's Euro V-compliant predecessor, and in average service with mileage of around 81,000 miles a year, a Mercedes-Benz Actros COE with the OM 471 will consume around 300 fewer gallons of fuel and emit around 3 tons less carbon dioxide.

Except for a few small differences, this latest version of OM 471 will appear under North America hoods in 2016 as the next generation DD13 from Daimler Trucks North America.

The commonalities stem from Daimler's Heavy Duty Engine Program that emerged in the early part of the previous decade. It was the company's objective then to build several engine platforms that could be deployed globally with a majority of shared components and systems. The DD13 was launched in North America in 2009, and introduced in Europe two years later. They were different enough at the time to meet local emissions constraints as well as market preferences and customer needs.

Come next year when the new version of the DD13 is introduced here, the two engines will be nearly identical, sharing most of the same part numbers.

"We've seen these two engines moving much closer together over the last few years," says Jim Gray, senior manager, NAFTA Life Cycle Management, Daimler Trucks North America. "Europe and the U.S. now share very similar emissions cycles though not identical, and we're working toward many of the same goals such as improved fuel economy, reducing internal mechanical drag, etc. Not long ago North American and European engines had to be different to meet various market demands, but even those demands are becoming more closely aligned than ever before."

Gray says there will be some external difference to accommodate the COE chassis, and the ratings will stay slightly different as well.

"The DD13 ratings will extend further to the bottom end because we don't have the 10.7-liter displacement," he says. "Conversely, the OM 471 goes a little higher on the top end because they don't use the DD15 there. They jump right to what we call the DD16."

One of the big differences between North America and Europe is the push to downspeed the drivetrain. We get there with different injection strategies and customized fuel maps that are a little different to what European customers are looking for.

We won't know until later this year what rating the 2016 DD13 will be offered with, but here are the published ratings for the Euro VI-compliant Mercedes Benz OM 471:

310 kW (421 hp) at 1600 rpm       2100 Nm (1550 lb-ft) at 1100 rpm

330 kW (449 hp) at 1600 rpm       2200 Nm (1625 lb-ft) at 1100 rpm

350 kW (476 hp) at 1600 rpm       2300 Nm (1700 lb-ft) at 1100 rpm

375 kW (510 hp) at 1600 rpm       2500 Nm (1850 lb-ft) at 1100 rpm

390 kW (530 hp) at 1600 rpm       2600 Nm (1900 lb-ft) at 1100 rpm