WEST PALM BEACH, FL – The long-awaited Detroit DD8 diesel engine this week entered into serial production in Redford, Michigan, and also was unveiled to Daimler Trucks North America customers and journalists at a race track outside of West Palm Beach, Florida.

The new engine is designed to be a low-maintenance, higher torque and higher horsepower option for fleets such as construction, dump, mixer, plow, fire and rescue and other tough duty applications. The engine joins Detroit’s previously released DD5 diesel engine, which is designed for urban applications such as last mile and P&D. According to Kelly Gerdert, director of product marketing, Freightliner and Detroit Components, the engine marks the end of a $375 million investment made by Daimler to round out its medium-duty diesel portfolio in North America.

The engine isn’t technically new, however. Gerdert noted Daimler leveraged all of its global engineering design assets in developing the engine, including input from the company’s European and Asian business units. The DD8 first debuted in Europe in 2015, which means it has five years’ of real-world driving miles behind it, Gerdert added. Other than a few tweaks to meet certain North American regulatory standards or customer preferences, the engine is largely the same as the ones running in Europe today.

Beginning this week, the Detroit DD8 can be spec’d for Freightliner M2 106, 108SD and 114SD truck models.

The DD8 is an inline, 6-cylinder 7.7L diesel offered in two basic configurations: a single-stage turbocharged version designed for maximum fuel economy, and a dual-stage turbo version that delivers higher horsepower and torque. Power ratings from the engine range from 260 to 375 hp, with engine torque ranging from 660 to 1,050 lb-ft of torque. And, according to Brian Daniels, manager, Detroit Powertrain and Component Product Marketing, it has a B10 life of 400,000 miles, which means engineers predict that 90% of the engines sold will make it to that mileage point before failure. He noted that the DD8’s 3 year/250,000 mile warranty reflects the engine’s robust design and longevity in tough trucking applications.

“The DD8 is built for performance with features that meet the needs of those specialized segments,” Daniels said. “Additionally, a big differentiator for the Detroit brand is the Detroit Connect Virtual Technician remote diagnostics system, which is available as standard on both the DD5 and DD8 engines. Virtual Technician helps fleets make informed service decisions within minutes of an engine or aftertreatment fault event, increasing uptime.”

Around Town with Detroit’s New DD8                                                

I was given the opportunity to drive several medium-duty Freightliner trucks equipped with the new DD8 engine, both on a closed course and in heavy city traffic, to see for myself how the new design handles itself on the road.

Popping the hood on a Freightliner M2, a quick once-over confirmed several points from our technical briefing earlier in the day. As with its little brother DD5 engine, the DD8 is extremely easy to access for both daily checks and more in-depth maintenance work. The fuel and oil filters feature a cartridge design for fast, clean change-outs. And all routine service points have been grouped together logically and placed as low as possible on the engine to facilitate fast and easy maintenance.

Walking toward the back of the truck, I was able to check out the new aftertreatment system. Freightliner has actually designed two different aftertreatment systems, a horizontal/inline configuration that hugs the rear frame rail, and a horizontal/understep design that can be placed underneath the steps leading to the cab. The goal here, Daniels explained, was to give more options to body upfit companies and make installations easier.

Turning the key, the DD8 dutifully shuddered to life and came up to idle quickly and smoothly. One of the DD8 features designed with the vocational market in mind is variable exhaust cam phasing, used at low engine speeds to increase exhaust temperatures and increase uptime by reducing the need for manual regenerations. Daniels warned me that this feature gives off a bit of a low-end, throaty grumble at idle. But I found the rumble barely noticeable and in fact forgot about it until my passenger pointed it out while we were waiting for a traffic light to change.

What is noticeable, however, is the low volume of engine noise that does find its way up from the engine compartment into the cab. The DD8 is a remarkably quiet design at both ideal and cruise speeds.

I drove both the single- and dual-stage turbocharged versions of the engines. Both were impressive in terms of low-end power and torque. But the higher-horsepower, dual-stage turbo version is very impressive with how fast it digs in and accelerates from a dead stop. Even loaded its 30,000 pounds, I wouldn’t be surprised to see a truck fitted with one hit 50 mph on a quarter mile run. Throttle responses are crisp, with no noticeable lag time between inputs and engine response. And the engine’s exhaust brake is equally impressive, delivering steady, forceful braking power once you take your foot off the throttle. In fact, I liked the exhaust brake quite a bit, as it started out with smooth, measured braking force that gradually increased as the truck’s forward motion slowed, without any harsh jerking or jarring that you sometimes get with aggressive engine brakes.

Daimler says customer interest in the new engine is high, and it’s easy to understand why. The new DD8 will be a welcome addition to Freightliner medium-duty fleets that need a bit more power to get their work done quickly and efficiently.