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Detroit DD5 Engine

New Clean-Diesel Engine Technology Means Cleaner School Buses

New clean-diesel school bus engines utilize cutting-edge technology, are 90 percent cleaner than they were in 2006, are more reliable and easier to maintain.


Diesel school bus engines are nothing like they were 10 or 15 years ago.  Today’s clean-diesel engines are more innovative and 90 percent cleaner than they were in 2006, and are becoming more innovative every year.  In fact, Thomas Built Buses, along with Detroit, is debuting the school bus market’s newest clean-diesel engines with the Detroit™ DD5™ and DD8™ engines this year.

While older diesel engines were powerful, they also caused aftertreatment maintenance headaches and sooty exhaust.  Today’s clean-diesel engines have improved dramatically and are not only just as powerful, but easier to maintain, more efficient and significantly cleaner than their predecessors.

New Technology Means More Power, Lower Emissions and Cost Savings

Newer clean-diesel engines, like the DD5 and DD8, are engineered from the ground up to meet 2017 Greenhouse Gas (GHG17) standards and beyond.  Based on EPA regulated emissions, these remarkable engines are comparable to or even cleaner than other alternative-fuel engines, all while remaining powerful, reliable and highly efficient.

Engine technology such as optional high-performance integrated engine brakes and variable-speed fan / advanced cooling systems enable these new clean-diesel engines to provide superior performance with greater efficiency. For example, the high-performance engine brake allows braking to occur at lower engine speeds where less fuel is being used.  At the same time, the variable-speed fan and advanced cooling system generate airflow to the engine at precise times while operating without the fan running constantly.  Just these two innovations mean the engine can perform with increased efficiency, improved fuel economy, reduced emissions and lower operating costs.

State-of-the-Art Innovations Mean Easier Serviceability and Decreased Maintenance

Today’s clean-diesel engines, like the DD5 and DD8, are also a breath of fresh air for school bus maintenance technicians. They offer some of the longest service intervals in the industry and easy access to oil and fuel filters.  But the most highly anticipated feature is the new advanced variable cam-phasing technology. This state-of-the-art feature helps increase exhaust temperatures for effective DPF regeneration in all conditions. The result is efficient aftertreatment system performance, decreased aftertreatment maintenance issues, increased engine efficiency, fuel economy and, most importantly, reduced emissions.

Both engines will include the Detroit Connect Virtual Technician remote diagnostic service.  Virtual Technician is a game-changer in the school bus industry.  Virtual Technician will help you make informed maintenance decisions, so you only service your buses when needed. When one of your buses has to go into the shop, Virtual Technician, with the backing of the experts at the Detroit Customer Support Center, will provide access to in-depth diagnostic information to get your bus repaired as quickly and accurately as possible, improving uptime.

With innovative technology, school districts, which already know and love diesel, can look forward to an exciting future of powerful, proven, reliable and clean diesel engines.

To learn more about the many benefits of clean-diesel school buses visit our Facts About Fuels page.


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