NAPA VALLEY, Cal. — Detroit Diesel’s popular DD15 engine has a new little brother.

The 12.8-litre DD13 was introduced to unsuspecting trade press editors at a Sterling Trucks event here yesterday. The six-cylinder, in-line engine will be well-suited to applications where Sterling has a strong presence, namely LTL, regional distribution and vocational markets.

The engine, which will replace the MBE4000, will be available with 350 to 450 hp and 1,350 to 1,650 lb.-ft. of torque.

The DD13 was built with reliability in mind, and has a B50 rating of one million miles, meaning 50% of the engines will last a million miles. By comparison, the Series 60 had a B50 rating of 750,000 miles, Detroit Diesel officials announced.

The DD13 is expected to provide 5% better fuel mileage than the MBE4000, thanks to an efficient amplified common rail fuel system.

“The DD13 is the only engine in its class to offer ACRS,” said Admir Kreso, director HDEP engineering with Detroit Diesel.

Unlike the DD15, the newest member of the family will not use turbo-compounding, because Detroit Diesel engineers wanted to allow for rear-PTO capabilities. The DD13 shares 65% of its parts with its larger brother, simplifying maintenance and repairs for fleets using both engines.

“We have taken all of the lessons learned from our 70 years of building engines and applied this extensive history to our new engine,” said David Siler, director of marketing with Detroit Diesel. “The DD13…delivers what our customers want: economy, serviceability and performance.”

The DD13 weighs about 400 lbs less than the DD15, albeit it’s slightly heavier than the MBE4000. Siler said the engine boasts a wide sweet spot and pulls strong down to 1,100 RPM. Its peak torque band is 500 RPM wide, Siler said. It also features an enhanced cooling system that minimizes fan-on time, saving fuel.

Another benefit of the DD13 is its extended service intervals. The engine can go up to 50,000 miles before requiring routine maintenance such as oil and filter replacements. The DD13 will initially be available in Sterling and Freightliner trucks beginning in 2009. Western Star will receive the engine in 2010.

For a more detailed look at Detroit Diesel’s newest engine, see an upcoming issue of Truck News and Truck West.