Ford’s diesel-hybrid Meta One concept car, unveiled at NAIAS (earlier post), combines a 2.7-liter twin-turbocharged V-6 diesel engine and an electric motor in the Modular Hybrid Transmission to create the first Partial Zero Emission Vehicle (PZEV)-capable diesel.

To meet PZEV requirements, a vehicle must meet SULEV-2 emissions levels combined with a 15 year/150K mile emissions warranty and a zero-evaporative fuel system.  (See Table 1 at bottom.) There are only some 16+ 2004 models from 10 different automakers meeting PZEV requirements, among them the Ford Focus and the hybrid Escape (AT-PZEV for Advanced Technology PZEV).

As the world’s first PZEV-capable diesel, the Mercury Meta One concept shows that advanced technologies that we’re developing promise the potential to deliver diesels that can be as clean as the cleanest gasoline engines. The torque of this engine, when combined with the modular hybrid-electric transmission, also provides excellent driving performance.

—Gerhard Schmidt, vice president, Ford Research and Advanced Engineering

The Meta One diesel engine, a variant of the new diesel in the Jaguar S-TYPE in Europe, delivers 248 hp (185 kW) of power and 431 lb-ft (651 Nm) of torque—torque equivalent to one of Ford’s large V-10 gasoline engines.

The engine is built on a Compacted Graphite Iron (CGI) engine block. Compared to conventional cast iron, the CGI material’s matrix microstructure is twice as strong. The CGI engine block handles higher power levels, emits less noise and can be made considerably lighter, thus improving a vehicle's acceleration, braking, handling and ride. Available now in production form in Europe, this engine is the first high-volume application of CGI technology.

Topping the CGI block are four-valve aluminum cylinder heads and a common-rail injection system that meters fuel at pressures up to 1,650 bar (24,000 psi) for precise control of each combustion event.

The Modular Hybrid Transmission replaces the torque converter of a six-speed automatic transmission with a 35 kW electric motor and two hydraulic clutches (from BorgWarner) that permit the motor to operate either independently of or in concert with the engine. The hybrid system supports start-stop functionality and regenerative braking. A 325V NiMH battery pack provides energy storage for the motor.

In a diesel application, the hybrid system is especially useful in reducing the conventional transient spike in emissions that occurs as the turbocharger comes up to speed when the vehicle starts form a stop. By using the tractive capability of the electric motor, the diesel hybrid can accelerate briskly while maintaining low tailpipe emissions.

Key system features of the Meta One that enable it to be the first PZEV-capable diesel include:

• Dual pre-turbo metallic oxidation catalysts for faster light-off and reduced cold-start emissions

• Diesel oxidation catalysts to reduce hydrocarbon and carbon monoxide emissions

• A selective catalytic reduction (SCR) system that uses urea to control nitrogen oxide emissions

• A catalyzed diesel particulate filter for soot reduction

• Dual-wall, air-gap exhaust pipes to retain heat in the after-treatment system and improve after-treatment efficiency

• A hands-free, capless fuel filler

As a final positioning fillip, Ford stressed the ability of the Meta One to run on Fischer-Tropsch diesel (FTD)—a synthetic Gas-to-Liquids fuel created from a variety of feedstocks including natural gas and biomass. This is a theme close to Volkswagen’s, and for a similar reason—the importance of the diesel platform. We’ll see if Ford further develops this theme through the year.

There was no data provided about fuel consumption. That, combined with the emphasis on the PZEV status of the diesel, reinforces a growing sense for me that in the short-to medium-term, diesel-hybrid applications will focus more on emissions control than on radical enhancements in fuel economy. Some of the data emerging from field trials and deployments of diesel hybrid system supports this. Fuel consumption (especially on highway) remains high, or in some cases, even greater, than conventional diesel systems. But the emissions produced are unarguably lower.

Table 1. To achieve PZEV status, a vehicle must combine SULEV-2 emissions with zero evaporative emissions.