Subaru’s Partial Zero Emissions Vehicle (PZEV)

What's a PZEV?

The Subaru PZEV (Partial Zero Emission Vehicle) is the affordable, no-compromise, eco-friendly alternative. Although the Subaru PZEV runs on regular unleaded fuel, it offers significant smog-reducing environmental benefits and delivers equal performance compared to non-PZEV cars or SUVs, including hybrids, diesels and alternative fuel vehicles.

A PZEV is classified as the cleanest-running gasoline-powered car on the market and was developed to meet the air quality standards of California, the most stringent in North America. A PZEV must meet the Super Ultra Low Emissions Vehicle (SULEV) tailpipe standard and have zero evaporative emissions.

PZEV certified Subaru vehicles come equipped with advanced gasoline engines that produce ultra-clean emissions with zero evaporative emissions. CARB requires zero fuel evaporative emissions in order to qualify for PZEV. However, PZEV vehicles are sold in all 50-states with the same strict requirements. All Subaru vehicles with a 2.5-liter naturally aspirated engine meet the stringent Super Ultra Low Emission Vehicle exhaust emission standard (SULEV). Subaru's environmental commitment to meeting PZEV standards is what makes a Subaru a Subaru.

Advantages
Subaru PZEVs allow drivers to reduce their impact on the environment while sacrificing nothing by delivering a win-win combination of advantages:

Immediate environmental benefits
No change in performance
Hassle-free ownership
Exceptional safety
Japanese reliability
Affordability
No complicated technology
Uncompromised versatility
No Alternative fuels required
Zero-Landfill manufacturing

How does it work

With Subaru PZEV vehicles, the remarkable reduction of smog-forming emissions is achieved through modifications in four key areas:

	Catalytic converter A larger and finer mesh of catalyst-lined passageways within a Subaru PZEV catalytic converter greatly contributes to its ability to reduce emissions. Along the entire length of the mesh are precious metals (catalysts) whose role is to change the molecular structure of the offensive emissions that try to pass through. In fact, the contact area is almost twice that of a traditional catalytic converter, producing a much more effective conversion of pollutants.
	Fuel injectors The fuel injectors on Subaru PZEV vehicles close tighter than conventional injectors to prevent evaporative emissions from fuel leakage into the intake manifold.
	Dual-filtration air-intake system In a conventional vehicle, unburned gas fumes can escape through the engine's air intake once the engine is shut off. To prevent this, Subaru PZEVs are equipped with a charcoal canister in the air intake that absorbs these evaporative hydrocarbon emissions.
.	Engine Control Module (ECM) Vehicle emissions are worst in cold start conditions. Subaru addresses this problem by altering the programming in the Engine Control Module to delay ignition timing, making the exhaust gasses hotter, which helps the catalytic converter heat up sooner, reducing emissions.