A common rail injection system for the next generation of medium duty diesel vehicles has been developed by Delphi Corporation. Based on the company's Multec technology, MDCR1800 (Medium Duty Common Rail) addresses the growing need worldwide for engines from four to nine litres that offer low emissions and car-type refinement combined with the durability and economy demanded by commercial vehicle users.

Three areas of application are anticipated: off-highway, commercial vehicles and large passenger vehicles such as North American SUVs. "We see growing demand for state-of-the-art diesel engines in all of these sectors," stated Peter Lakin, business line executive for Diesel Systems.

"Delphi's new MDCR technology will help engine and vehicle manufacturers meet this demand with a technology that offers world-class performance yet, thanks to our established volumes and proven technologies, is also dependable and affordable."

Starting in 2006, off-highway vehicles sold in the USA must comply with rigorous Tier III emissions regulations. In Europe, the broadly equivalent Stage IIIA regulations will be introduced in 2006 - 2008. For the higher rated engines, compliance will require a substantial step beyond the traditional injection technologies used by the majority of today's medium duty applications.

Delphi's new injection system is based on selected components from its Multec DCR (Diesel Common Rail) light duty system. More than four million and a half DCR systems have been produced since its introduction in 2001.

At the heart of the new medium duty system is an advanced solenoid injector that Delphi says allows the smallest injection quantities and highest precision fuel delivery of any common rail system available today, including those using first generation piezo injectors. The system has a maximum rail pressure of up to 1,800 bar and can deliver up to five injection events, giving engine designers flexibility to select the most appropriate combination of durability, driveability, noise and emissions.

Control over each event is so precise, claims Delphi, that the system can enable compliance with Tier III regulations for off-highway vehicles at 1,400 bar with just two injection events and no aftertreatment.

"MDCR 1800 allows a big leap in performance, refinement and emissions without substantial re-engineering of existing engines or the cost of bespoke, low-volume direct injection systems," concludes Peter Lakin. "It presents exciting opportunities for both Delphi and our customers."