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US: GM plans new small turbodiesel V8

By just-auto.com editorial team | 25 August 2006

General Motors will introduce a new V8 turbodiesel that improves engine fuel efficiency by 25% for North American light duty trucks (under 8,600 pounds gross vehicle weight) after 2009.

The premium V8 diesel is expected to deliver class-leading torque, power and refinement while maintaining a significant fuel efficiency advantage over comparable output petrol engines.

The new dual-overhead cam, four-valve V8 diesel engine will fit within the same space as a small block V8 petrol engine. This compact size is made possible by using an integrated air system and narrow block.

"This new GM light duty diesel is expected to become a favourite among customers who require excellent towing ability and fuel efficiency," said Tom Stephens, group vice president, GM Powertrain. "It will meet the stringent 2010 emissions standards, and it will be compliant in all 50 states, making it one of the cleanest diesel vehicles ever produced."

Environmental benefits of the new engine include a 13% reduction in CO2 compared with petrol engines, and at least a 90% reduction in particulates and NOx compared to diesel vehicles today. This will be GM's first engine to use a NOx after-treatment system with a diesel particulate filter to help achieve the Tier 2 Bin 5 and LEV 2 emissions standards.

Technical highlights of the engine include aluminium cylinder heads with integrated manifolding, compacted graphite iron (CGI) block for a strong engine base and fracture-split main bearing caps and connecting rods for a precise fit. A high-pressure, common-rail fuel system is used, which has the ability to inject fuel five times per combustion event to control noise and emissions.