HIGH POINT, N.C. — Thomas Built Buses is now accepting orders for school buses equipped with Detroit DD5 and DD8 engines.

The DD5 engine is a 5.1L in-line four-cylinder engine adapted specifically for the Thomas Built Buses Saf-T-Liner C2. It offers a 200 to 240 horsepower range and a torque range of 560 to 660 lb.-ft.

The Detroit DD8 engine is a 7.7L in-line six-cylinder medium-duty engine, specifically developed for the Thomas Built Buses Saf-T-Liner HDX. It provides a horsepower range of 260 to 300 and a torque range of 660 to 860 lb.-ft.

Both the DD5 and DD8 feature power and best-in-class fuel economy thanks to a state-of-the-art design that allows usable power and torque to be reached at lower engine speeds. School districts can expect at least a 3% improvement in fuel economy compared to other diesel engines in the category, according to Thomas Built Buses.

Longer service intervals also are a key differentiator, with oil and filter change intervals up to 45,000 miles (or either 18 months or 1,500 hours, whichever comes sooner.) The Detroit engines feature top-load oil and fuel filters for easier serviceability, according to the manufacturer.

“We’ve been waiting for this day for a long time,” said Caley Edgerly, president and CEO of Thomas Built Buses. “Both of these engines were developed from the ground up specifically for the medium-duty industry.”

Edgerly added that the clean-sheet design of the engines is only new to the school bus industry: the proprietary engine platform was launched in Europe in 2013.

More than 90,000 engines are running on this platform successfully today, he said.

Both engines come with Detroit Connect Virtual Technician remote diagnostic service, which is designed to help transportation directors make informed maintenance decisions so buses are serviced only when needed. Virtual Technician, with the backing of the Detroit Customer Support Center, provides access to in-depth diagnostic information to get buses repaired as quickly and accurately as possible.

Both engines were built to produce fewer emissions, so they meet 2017 greenhouse gas (GHG17) standards, and will continue to meet emissions standards through 2020, according to Thomas Built Buses. The DD5 and the DD8 also employ technology such as a variable cam exhaust phasing, which is engineered to allow additional heat to the exhaust stream. This enables efficient operation of the school bus’s aftertreatment system in low-speed, stop-and-go operations.

Customers can contact their local Thomas Built Buses dealer for more information on these engines.