|2006 Ford Fusion|
The 2006 Ford Fusion and Mercury Milan mid-size sedans, both derived from the CD3 architecture, are entering the market this fall as California Partial Zero Emission vehicles (PZEV) when using the 2.3-liter Duratech inline-four engine.
The Ford Fusion and the Mercury Milan will be Ford’s third and fourth PZEV vehicles, following the Escape Hybrid and the Focus PZEV. (Mazda and Volvo, also part of Ford, have six in total.)
To qualify as a PZEV, vehicles need to meet three basic criteria:
Meet the Super Ultra-Low Emission Vehicle standard (SULEV)
Eliminate fuel-system evaporative emissions
Ensure these criteria will be met for an extended lifetime of 15 years or 150,000 miles
|Current California PZEVs (non-electric)|
(Mazda, partly owned by Ford, has two PZEV models, and Volvo has four. GM, by comparison, has none. Toyota has two—the Prius (AT-PZEV) and the Camry (PZEV); Honda has six: Insight, Civic Hybrid, Civic GX, three Accord models, including the hybrid.)
The PZEV Fusion and Milan both use the 2.3-liter Duratec inline four engine. The four-cylinder engine delivers 160 hp (119 kW) and 203 Nm of torque, and can be paired with a five-speed manual or automatic transaxle.
The standard Duratec 23 and five-speed manual returns 23 miles per gallon (mpg) city, and 31 mpg highway.
To attain PZEV rating, Ford made a number of improvements to the induction, calibration and exhaust systems of the Duratec 23 to achieve LEV II certification. From that point, the powertrain team identified ignition and evaporative emissions to qualify for PZEV certification.
Ninety percent of the improvement in emissions is achieved in the first 20 seconds of startup. In light of that, we focused most of our efforts on those first seconds after engine ignition...—Gary Zabkiewicz, Ford
One of the changes to improve emissions at startup includes a ported electronic thermactor air system, which injects metered thermactor air into the intake manifold. (The thermactor is similar to a catalytic converter and is located in the exhaust system between the exhaust manifold and the catalytic converter.) The warmer air and additional oxygen enable more combustion and decrease the amount of unconsumed gasoline in the system.
|The PZEV Duratech 2.3-liter engine. Click to enlarge.|
Additionally, recycling cold-start exhaust back through the engine provides a second opportunity to trap emissions after the catalysts reach operating temperature.
To enable the catalysts to reach operating temperature faster, the team replaced the standard Duratec 23 cast iron manifold with a stainless steel, dual-walled manifold, which heats up faster than the cast iron design.
To boost the efficiency of the engine, the Duratec 23 features Charge Motion Control Valves (CMCV) in the intake runners—similar to those found in the F-150 pickup—to increase torque and improve combustion at low engine speeds.
An air-fuel mixture entering an engine behaves differently at different engine speeds and loads. At low engine speeds and light loads, relatively little air-fuel mixture is drawn into the cylinders in a given time period, so it moves relatively slowly through the intake runners and into the cylinders. At high engine speeds, the intake mixture speeds up, as a larger volume passes through the intake runners over the same time period.
One of the challenges involved in maximizing efficiency out of each drop of fuel is to assure that it mixes thoroughly with air, in the right ratio, before it is burned in the cylinders—a task more easily accomplished when the air is moving quickly.
At low speeds and lighter loads, the electronically controlled Charge Motion Control Valves—metal flaps at the end of each intake runner—close leaving only a small opening. Air jets through this gap, creating a tumble effect in the combustion cylinder and forcing fuel to mix more thoroughly and burn quickly and evenly. The CMCVs open to predetermined points as the engine revs up. At higher speeds, the valves do not affect the intake, letting maximum flow into the combustion chamber at wide-open throttle.
The Milan and Fusion both offer a 3.0-liter V-6 engine with more power (221 hp; 165 kW) and torque (278 Nm)—but not a PZEV certification.
The Milan and Fusion are the targeted platforms for the application of Ford’s first sedan-based hybrid powertrain in the next few years. Given their size and performance options, they will be competing with the Toyota Camry hybrid, the Honda Accord hybrid and the Nissan Altima hybrid. It will be interesting to see how each automaker applies their hybrid technology (e.g., performance or efficiency, downsizing, and so on) to differentiate and compete.
|Select PZEV Mid-size Sedans|
|Displacement liters (cc)||2.3 (2,261)||2.4 (2,361)||2.4 (2,354)||2.5 (2,488)|
|Power hp (kW)||160 (119)||151 (113)||166 (124)||175 (131)|
|Fuel economy mpg city/highway||23/31||24/34||26/34||23/29|
Driveclean.ca.gov—a zero and near-zero emission vehicle guide from California’s ARB