What’s So Great About Partial Zero-Emissions Vehicles? A Guide to PZEVs

If you live in California or any state with strict emission standards, then you’ve probably seen a lot of vehicles with a PZEV sticker. You no doubt wondered to yourself, “What does PZEV actually mean?”

Well, today’s the day you finally get your answer: PZEV stands for partial zero-emission vehicle, and a PZEV sticker means that the vehicle is considered to be a partial zero-emission vehicle.

What Is a Partial Zero-Emission Vehicle?

You’ll find plenty of environmentally friendly cars in the market, but not all of them can be considered a PZEV. Partial zero-emission vehicles have three distinct characteristics that set them apart from other vehicles:

• Have fuel systems that produce no evaporative emissions
• Meet the same strict tailpipe emission standards that super ultra-low emissions vehicles (SULEV) do
• Have emissions control parts covered by a 15-year or 150,000-mile warranty

In other words, a PZEV is exactly what its name suggests: a vehicle that produces zero evaporative emissions.

What Is the PZEV Engine Like?

As the cleanest-running gasoline-powered vehicle on the market, PZEVs are no doubt one of the most impressive vehicles you’ll find today. They come with plenty of environmental benefits without sacrificing any of their power and performance, all thanks to their unique engines.

Anti-Permeation Fuel System Liners

Regular engines often have higher emission levels due to a high saturation of gas in their fuel systems, causing fuel vapor to leak out and evaporate.

Thanks to their anti-permeation fuel system liners, PZEV engines don’t have to deal with any of that. Their special fuel system liners prevent fuel leakage and keep the environment safe from fuel vapor.

Carbon Air Intake Traps

When you turn off a regular engine, fuel vapor is sometimes left sitting in the combustion chamber, where it can escape through the engine’s air intake and increase emissions.

With PZEVs, this isn’t an issue at all. PZEV engines have a dual-filtration air-intake system that absorbs fuel vapor before it can escape through the air intake system.

Close-Coupled Catalytic Converters

If you’ve ever driven a PZEV before, then you’ve probably noticed how fast its engine speeds up compared to regular vehicles. This is because PZEV engines have close-coupled catalytic converters which convert emissions into less harmful gases while revving the engine quickly.

These catalytic converters are lined with precious metals that change the molecular structure of nitric oxide and nitrogen dioxide before they can escape your vehicle.

Powertrain Control Module

Did you know that cold starts aren’t an issue with some PZEVs? For example, Subaru PZEVs have special modifications added to their powertrain control modules (PCM) to delay ignition timing. This helps the catalytic converter heat up faster, which reduces emissions.

Carbon Canister Scrubbers

As an extra safety measure, PZEVs also have carbon canister scrubbers to prevent any fuel vapor from escaping through the fuel cap. These scrubbers are installed in the vehicle’s fuel line, where they trap fuel vapors and destroy them in the combustion chamber.

What Are the Benefits of Owning a PZEV?

Did you know that PZEVs don’t just benefit the environment but also their owners? Owning a PZEV comes with its own share of advantages, such as the following:

Smog Reduction

The great thing about PZEVs is that they guarantee smog reduction without compromising engine performance. Because of this, some states will even exempt you from smog checks if you own a PZEV, saving you both time and money.

Low Maintenance

Contrary to popular belief, PZEVs are pretty low maintenance. Their engines are designed to last longer than regular engines, so they’ll require less maintenance over the years. This can help you save up on repair costs, especially because most manufacturers offer extended warranties of up to 150,000 miles.

Higher Resale Value

If you ever change your mind about wanting a PZEV, you can always sell it in the future. You don’t have to worry too much about your losses either. PZEVs aren’t as common as regular vehicles, so they’re usually in high demand. You can probably sell them for higher than most old regular vehicles go for.

What Are the Cons of Owning a PZEV?

Of course, no vehicle comes without its fair share of disadvantages. While PZEVs can greatly benefit you as an owner, you should also consider these cons:

Higher Purchase Price

If you’re in the market for your own PZEV, then expect a higher purchase price. PZEVs typically cost more than regular vehicles because of their extra features, but their final price will still depend on their make and model. For example, you can expect the price of a 2015 Lincoln MKZ Hybrid to greatly differ from the price of a 2012 Honda Civic Natural Gas.

Reduced Fuel Economy

Unfortunately, all of that extra emissions control equipment means PZEV engines work a lot harder than regular engines. This means they’ll also consume more fuel than your average vehicle.

Where Can You Find PVEZs?

Originally, PVEZs were first manufactured in California as a compromise between auto manufacturers and the California Air Resources Board (CARB). In an effort to reduce emissions, the state of California required automakers to produce at least 2%  zero-emission vehicles (ZEVs) in 1998.

Unfortunately, auto manufacturers struggled to meet this requirement, so the CARB agreed to adjust the mandate to allow them to earn credits with PZEVs instead. Soon after, several other states followed suit, including New York, Massachusetts, and Oregon.

As the market for PZEVs became more competitive, various manufacturers such as Ford, Honda, and Subaru all developed their own versions of PZEVs. Nowadays, you’ll find PZEVs all over the country, with other variations on the market too, such as hybrid-electric PZEVs and advanced technology partial zero emission vehicles (AT-PZEVs).

As auto manufacturers continue to devote themselves to creating environmentally friendly vehicles, you can look forward to more variations of PZEVs in the future.