2012 Subaru Impreza Premium PZEV

What is PZEV anyway?

It doesn't have anything to do with peace or electric vehicles. We'll dissect a Subaru Impreza Premium PZEV for answers to this conundrum of marketing, science, and politics. Mostly politics.

It's likely you've seen the term "PZEV" on a vehicle recently. You might have even assumed it was some kind of hybrid or green vehicle. If you guessed the latter, you'd be close.

The "EV" in the term PZEV doesn't stand for "electric vehicle" as we've come to know the acronym. Instead, PZEV stands for Partial Zero Emissions Vehicle. It's a sort of mashup category of cars created almost entirely through politics.

Recently, the question came to the fore when I was test driving a 2012 Subaru Impreza Premium PZEV. The Impreza features a nice, shiny little symbol on the trunk with PZEV sprouting a leaf. When talking to people about this neat little car, they inevitably assumed that this symbol meant it was a hybrid-electric of some kind. After explaining what it really meant a few times (often to dumbfounded expressions), I realized that most people aren't really familiar with the term or what it's for. And many find it incredulous once they do find out about it. At least, people who live in Wyoming do. I didn't ask anyone in Jackson Hole (Wyoming for "California") about it, honestly.

What is a PZEV then?
A partial zero emissions vehicle has a PZEV engine or drive train that meets or exceeds specific requirements set forth by the State of California. It's almost 100% politically-created since the criteria have as much to do with warranties and getting around other California mandates as they do with emissions requirements.

The Subaru pictured, for instance, is a compact car that gets 27mpg city and 36mpg highway and sports all wheel drive - which where I live is a pretty good package all together given the amount of highway and semi-offroad (dirt, gravel) driving we do out here. For all that, the Impreza PZEV puts out 90% less emissions than its equivalent counterpart, meaning it meets federal super ultra low emission vehicle (SULEV) standards.

(Not just super, but super ultra.)

That alone doesn't make it a PZEV, though. To meet that distinction, it must be a SULEV and have zero evaporative emissions from its fuel system and have a 15 year/150,000 mile warranty on its emission control components. Having all of those things makes a car PZEV special.

Who came up with this idea?
Why the California Air Resources Board (CARB), of course - our nation's top think tank of acronym-laden vehicle requirements (A-LVR) and politically correct environmental mumbo-jumbo (PCEMJ). Why did CARB come up with PZEV? Why.. because another mandate they laid down, this one involving the term ZEV, was impossible for many automakers to meet. So PZEV became a compromise.

You see, not long ago, the out of touch with reality, but very environmentally conscious board members at CARB decided that all auto manufacturers should be required to produce a zero emissions vehicle (ZEV) or else lose their ability to sell cars in California. After much discussion, in which several professors of automotive design and never-had-a-real-job engineering espoused the wisdom of this approach, the board approved the idea. When auto makers got wind of this, they complained.

The complaints got even louder when TZEV (transitional zero emissions vehicles, formerly AT-PZEV or Enhanced PZEV) vehicles were not included in this, but were given a special category all their own that would allow them to be transitional towards the ZEV requirement. After a lot of explanation, mostly using single-syllable words, to the CARB people, automakers were able to convince them that you can't just take any car and throw batteries in it and have it work right.

Of course, just creating exemptions wasn't easy or simple enough, so CARB had to come up with a complicated scheme. They'd just returned from an important conference in which Al Gore explained carbon credits and thought the plan a great one, so they adopted something just as convoluted for ZEVs. So an automaker that can amass enough ZEV credits to match a percentage of the sales they have in California can keep selling cars in California and if they happen to amass extras, they can sell those to other automakers that otherwise might not have made their ZEV credit requirements for the year.

In this way, the CARB members could continue to claim that they are helping the environment and somehow creating green jobs and manufacturers can continue selling the SUVs and crossovers that consumers really want just by getting those not rich enough to buy a Tesla or a Leaf to buy cheaper PZEV cars instead. In the end, it all worked out for everyone and only required the slaughter of an additional 100,000 or so trees to keep the paperwork flowing, resulting in the addition of a handful of green jobs because someone had to be hired to do all that wood chopping and paperwork filing.


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Awesome. Best story in a long time on our site.
You are wrong. This is a poorly written rant about several subjects.
I searched "PZEV Subaru" to try to find out what the difference is between the PZEV models and the non-PZEV models. Instead I found this article written by some failed amateur author who managed to blog 13 paragraphs of adolescent filler. This goofy idiot tried to be informative and witty but failed on both counts. Here's a tip: If you title an article with a question like "What is PZEV anyway?" and introduce it with a leader like "We'll dissect a Subaru Impreza Premium PZEV for answers", then it's a good idea to provide that answer for the reader instead of going off on stupe tangents about slaughtered trees and blah, blah, blah, California is dumb, blah, blah blah... When you don't bother to provide any actual, useful information in your writing, you come across as some laid-off mechanic who didn't know the answer to his own question and just wasted the time of whoever read his article.
I defined it exactly for what it is: a political construct. The entire "What is a PZEV then?" section gives the details and the rest of this article explains why it exists in the first place. In short, it's a bullshit "environmental feel good" designation that means nothing, but gives California an excuse to give tax breaks via bureaucratic control. Here's a tip: before you criticize, actually READ.
I read your article. It was a waste of time. I found an article written by someone who actually explains the difference between a PZEV Subaru and a non-PZEV Subaru. Hopefully it'll help those people who accidentally stumble across your article in the future. Here's the link: bit.ly/ZqxWqG
Ya, great resource (not). Read it now you can see he just paraphrased the first half of mine and then cut-pasted directly from the Subaru PR materials.
I thoroughly enjoyed the read, the digs and the info. I get it.
I agree with Steven. I wanted info, not political diatribe.
Since it's a political construct, politics is what you'll get out of an honest look at it.
Aaron, your defensive attitude and lack of pose is making me, and I'm sure many others, incredible uncomfortable. You should expect criticism with every article you write. When you react this way, instead of not reacting at all, you're insuring that your readers leave this article unhappy and dissatisfied with the material.
Does a PZEV car use more fuel than a non-PZEV car ?
No. Not that it should come as a surprise to anyone that this article gets things wrong. PZEV is just about non-CO2 emissions, and does not noticeably affect fuel economy one way or the other.
Then why in Canada, a Subaru Outback, 2.5i , CVT transmission has a 40 mpg, compared to US model 2.5i, CVT @ 33 mpg Hwy? Almost 20% in fuel consumption? Same engine, same horsepower and torque, same car, where this big difference comes from? And look at Legacy model( Canada), and tell me what car (in USA), same size, gasoline engine and 4 wheel drive, will give you from a 2.5 engine 43 mpg?
Canada uses the British Imperial Gallon (4.5 liters) whereas the US uses the US Gallon (3.8 liters). So the Canadian gallon is about 18% larger which accounts for the 18% increase in fuel economy.
The difference in MPG Canadian VS US is the use of Imperial Gallons VS US Gallons. The U.S. liquid gallon and the U.S. dry gallon are different units defined by different means. The U.S. liquid gallon is defined as 231 cubic inches and equates to approximately 3.785 litres. One imperial gallon is equivalent to approximately 1.2 U.S. liquid gallons. Hence your MPG would be 20% higher.
Did Governor Brown choose a CA/DCA/BAR Chief who can find out if what is broken on a PZEV Smog Check failed car gets fixed? A Smog Check secret shopper audit would cut toxic car fleet impact 1500 tons per day while reducing cost by $billions.
I actually find this article rather useful. Anyone can figure out what PZEV is all about, but trying to figure out if it is cost effective to shell an extra $200 for a PZEV vehicle is the big question. As I suspected from this article and many other's I have read, it seems to be somewhat of a scam to benefit the automakers and CARB and the consumer ends up paying for it. I will definitely not pay extra for a PZEV car as it gives me no cost benefit, and the reduced emissions are nearly negligible. If CARB employees really want to clean up the environment, they wouldn't be paid $150,000 plus dollars to buy their gigantic SUVs.
Welcome to the world of socialism. Not too different from OZ is it?
Great explanation! Now it all just makes a little bit more sense. That last part though... reminds me of the old Communist Soviet Union (AKA California).
* Do you want $2 Gasoline at the pump? * Do you want clean air and water? Ethanol waiver and elimination of E-85 flex fuel credit can cut our ozone & CO2 transportation pollution over 50% Let’s improve performance of CA Climate change law AB 32 (Pavley) in 2015 for future generations
Look, if it gives off less CO2 by a substantial percentage that is a good thing for the environment, tax breaks or no tax breaks. Bitch about it all you want. The planet is warming based in part on the burning of fossil fuels. So if the state of California helps pay for the solution to the problem with tax breaks for those who want to drive a vehicle that is pretty damn environmentally friendly so be it.
It's not a substantial percentage and it's not proven that it does actually improve anything. I won't get into a global warming debate in this venue, but will point out that your parroting of contended science is incorrect.
If you're implying that human-caused impacts to global warming are not the most significant inputs to what have been measured as increasingly warming trends, then that helps explains your odd politicization of PZEV goals: about 30% reduction of volatile, nitrogen oxides and CO-related products from burning of fuel in cars. Any slowdown in our pace of generating pollutants from technology we wield can potentially be helpful, given that we're already on the path to hit a number of tipping points, as it is. Sure, methane and deforestation are large contributors to this picture, but technological waste products are fully in the mix of contributors - again, any improvements can help.
That big disc in the sky is the most significant input to global warming, not the CO-related products of burning fuel in (non-PZEV) cars....sheesh.
Well said Aaron! And thank you for the info. People do parrot the "global warming" bs, such a scam.
I'm confused, please share your opinion on GMO fuel ethanol mandate on CO2 and ozone.
I drive a 2015 ford PZEV Out of about 20 sales and service dlr employees the only PZEV opinion was a detailer About 2,000,000 Partial Zero Emissions Vehicles are on the road The first PZEV was a 2000 model nissan
people need this type of vehicle for health improvement.
I just wish call would remove that stupid acronym from my lift gate.
My understanding is that the main difference in PZEV and non is the evaporative emissions as someone wrote. I did not read all these posts but wanted to give my take. We have a 2008 Outback 2.5i Limited PZEV and the extended warranty alone is piece of mind as the converter alone is over 600 dollars. It has already been replaced once under warranty by subaru for Zero dollars at 80000 miles. Also the intake air box has a activated carbon screen to adsorb the fuel vapors emanating from the intake part of the engine. We get fuel vapors from injectors mostly and other unburned fuel sectors aka crankcase, cylinders a small bit. Also the injectors themselves are slightly modified to have more seating pressure i have been told, although i have not verified this one. Injectors do sometimes Drip, be fuel soaked at the tip and of course fuel evaporates (after all there job is to handle the fuel). In order to help lower emissions from millions of vehicles the automobile manufacturers and other EPA authorities such as CARB came to this brilliant (in my opinion) conclusion make a few simple changes. and extend the warranty. We were glade we had the option 8/)