Leave it to brain-dead Californian air regulatory bureaucrats to infuriate math purists everywhere by assuming that something called a Partial Zero-Emissions Vehicle, or PZEV, would make sense. Now, one of the things I have faith in when I get up each morning is that zero is still an absolute entity, no partiality about it. In offering a carrot to automakers who have to meet fleet emissions standards, California and like-minded states such as my own beloved New York have apparently deemed it appropriate to redefine laws of math, and created the acronym from hell in the process.

Pray there's a just reward for these nuts. In the meantime, you can't deny it's a good thing to encourage cleaner-burning rides, particularly when they've got the fun factor found in Ford's Focus, now available with an optional PZEV-compliant engine nationwide.

The engine is known in-house as the Duratec 23E, a dual-overhead cam, all-aluminum in-line four displacing 2.3 liters. First introduced halfway through the 2003 model year as standard equipment in California, New York, and Massachusetts, the great thing for gearheads is that the new mill ups the performance ante over the base 2.0-liter engine, providing 144 hp at 5750 rpm and 149 lb-ft of torque at 4200 rpm.

The torque spec is most significant, as it's 4 lb-ft greater and 1300 revs more accessible than that found in the enthusiast-oriented SVT Focus. Performance engineering that makes the world healthier for all is one delicious irony, don't you think?

For those of you keeping cleanliness scores, the 23E allows the Focus to meet another ridiculous California acronymic standard, SULEV (for Super Ultra-low Emissions Vehicle), which means it emits a mere pound of smog-forming pollution over 15,000 miles of driving. It also eliminates fuel-system evaporative emissions. 

Fuel economy numbers are respectable as well. EPA numbers of 25 mpg city, 33 mpg highway, are posted for the standard five-speed transmission; the optional four-speed automotive delivers 24/30 figures.

Tech aspects

This melding of performance and low emissions starts with an all-new aluminum block with a deep skirt that extends well below the crankshaft centerline to bolster stiffness. A separate cast aluminum alloy ladder frame carries the lower bearing shells. Dry, cast-iron bore liners are cast into the box. A structural ribbed aluminum oil pan and cast alloy front cover further stiffen the block and reduce engine noise. The extensive use of aluminum creates an engine that weighs 40 pounds less than the 2.0-liter Zetec mill. 

The head design uses direct-acting mechanical bucket tappets and an aluminum alloy "high flow" cylinder head with press-fit valve seats. A "pent roof" combustion chamber promotes circular flame propogation in improves fuel economy, say Focus engineers, particularly under partial loads. 

A new piston, ring, and connecting rod assembly reduces rotational weight by 15 percent, while the electronic coil-on-plug ignition includes a cylinder knock-control system to optimize performance and economy. 

An all-new intake manifold is fully symmetrical and made of friction-welded plastic to reduce flow friction and operating temperatures. The plastic also allowed Ford's engineers flexibility in creating a sporty, yet refined, engine song. Each of the manifold's four runners contains a butterfly valve that, at low speeds, induces turbulence that accelerates the air/fuel mixture into the combustion chamber, while opening fully at high speeds to meet the need for peak airflow. A solid-state temperature and pressure sensor improves precision of air mass calculations, which are constantly relayed to the electronic powertrain control module to maintain peak engine efficiency. A carbon trap in the intake collects vapors from residual fuel left at engine shutoff, reducing evaporative emissions, as does the use of stainless steel for the fuel tank, fuel lines and connectors.

Nitrous oxide emissions are reduced by an electronic exhaust gas recirculation system that meters the addition of burned exhaust gases to the intake charge. The extra mass of the intake charge acts as a heat sink to reduce combustion temperatures, which in turn cuts emissions.

The rear-facing four-into-one tubular steel exhaust manifold heats up more quickly than a cast-iron unit, which helps reduce cold-start emissions, as does the very close proximity of the high-density catalysts to the manifold.

Finally, twelve-hole fuel injectors discharge directly toward the twin inlet ports of each cylinder, enhancing atomization and penetration while reducing cylinder wall wetting, providing improved drivability and lowered emissions.

Bog

We were initially disappointed to see our Egg Yolk Yellow (Who thought up that name?) ZX3 hatchback tester was equipped with the same automatic transmission that had bogged down the 2.0-liter Duratec-fitted ZXT wagon we tested a year ago. The low shift points still hinder acceleration off the line, but the overall driveline package is now more in character with the chassis" excellent dynamics - this is as well-planted and responsive a ride as you'll find under $30,000, although I'd be inclined to give up some bump damping in favor of reduced body roll. The torque curve is broad and much improved at the low end over the 2.0-liter Duratec, the engine redlines at 7000 rpm, and parking the slushbox in second gear still provides a lot of fun over your favorite winding roads.

This is a great application for a great engine. The Duratec 23E is steadily finding broader applications in Ford's portfolio - in various guises, the 2.3 is currently available for the Ranger, the new Mazda MPV minivan, and Mazda6, and will be featured in the upcoming Ford Escape Hybrid and Ford Futura. In the Focus, however, it creates the performance benchmark for the economy car class, and leaves one feeling virtuous to boot.

 

2004 Ford Focus PZEV ZX3
Base price: $13,455; as tested, $18,775
Engine: 2.3-liter, DOHC PZEV in-line four
Drivetrain: Four-speed automatic/five-speed manual, front-wheel drive
Length x width x height (in): 168.1 x 66.9 x 56.3
Wheelbase: 103.0 in
Curb weight: 2612 lb
EPA fuel economy (city/hwy): 24/30 mpg (automatic)
Safety equipment: Four-wheel ABS, "Advance Trac" traction control, child seat anchor tethers, side-impact air bags (all included options on test vehicle)
Major standard equipment (premium package): Air conditioning, power windows/mirrors, AM/FM stereo w/CD player, cruise control, height-adjustable driver's seat, tilt/telescopic leather-wrapped steering wheel, 16x6 alloy wheels, 205/50R16 Firestone Firehawk GTAs, fog lamps
Warranty: Three years/36,000 miles

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