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PZEV = Partial Zero Emissions Vehicle, WTF is this?


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Yo,

I was somewhere in the galaxy the other month and saw a Partial Zero Emissions Vehicle badge on the back of a forester. I cant remember the trim level that it had, it was a rental i know because it had a fleet registration sticker and an enterprise logo on the back.

 

Does anyone own one of these Foresters? Or does anyone know anything about this model? Im off to check cars 101 on the issue right now.

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apparently, through whatever means, these cars put out extremely low emissions on their "smog index". like the average new car is rated at .39 and these PZEV cars are like .09.

I really think that the "partially-zero" designation is very misleading, since at no time the car produces "zero" emissions, as it is still a non-hybrid, internal combustion vehicle. since it isn't actually "zero" emissions, any emissions that it does produce is simply relative to whatever measuring scale you're using.,.... it sure isn't "partially-zero" compared to an actually ZERO emission vehicle.

like I said, I don't know the means by which this is all achieved, but I would guess an extremely high-efficiency catalyst is involved.

~Erik~

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  • 1 month later...

On a side note. If you know someone who owns one, try to be there when a PZEV starts 'COLD' . Very noisy and LOUD !! Until it warms up, the emissions vacuum and pump are vented to the atmosphere.

 

So older Subaru's have cold start piston slap, newer ones emission vales and vents.

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It seems there are some other PVEZ engines from other mfg that are a little odd on cold startup. This may be a charecteristic of whats required to make it PVEZ, not sure yet. Mot enough of them have been sold yet to find out.

 

nipper

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I just spotted this note on cars101.com tech tips page: "PZEV idle fluctuation (“hunting”) during cold starts which generally last about 20 to 30 seconds the cause is a combination of factors including

1. Fuel blends. 2. Percentage of Ethanol content of the fuel being used. 3. Outside Temperature. 4. Narrow operating range of the Air Fuel Ratio Sensor.

The main cause of this fluctuation is fuel related and not the vehicle.

PZEV engines are designed to run on fuel blended for distribution within certain areas of the U.S. (such as the state of California). Fuels in other markets that may have adopted California emission standards, may be a slightly different blend. If you live in any other state than California, your vehicle will operate on gasoline meeting Federal specifications. However, PZEV vehicles may experience this issue especially during the summer months when summer blend fuels are distributed. There is no effect on vehicle emissions, and no short or long term damage will occur due to this issue.

The condition may be reduced or eliminated by changing to a fuel that contains a lesser percentage or no Ethanol. Also, a light throttle application while the vehicle is exhibiting this condition will stabilize the idle. As we move towards cooler weather many areas of the country will be changing to a winter blend of fuel which may also alleviate the condition."

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I just spotted this note on cars101.com tech tips page: "PZEV idle fluctuation (“hunting”) during cold starts which generally last about 20 to 30 seconds the cause is a combination of factors including

1. Fuel blends. 2. Percentage of Ethanol content of the fuel being used. 3. Outside Temperature. 4. Narrow operating range of the Air Fuel Ratio Sensor.

The main cause of this fluctuation is fuel related and not the vehicle.

PZEV engines are designed to run on fuel blended for distribution within certain areas of the U.S. (such as the state of California). Fuels in other markets that may have adopted California emission standards, may be a slightly different blend. If you live in any other state than California, your vehicle will operate on gasoline meeting Federal specifications. However, PZEV vehicles may experience this issue especially during the summer months when summer blend fuels are distributed. There is no effect on vehicle emissions, and no short or long term damage will occur due to this issue.

The condition may be reduced or eliminated by changing to a fuel that contains a lesser percentage or no Ethanol. Also, a light throttle application while the vehicle is exhibiting this condition will stabilize the idle. As we move towards cooler weather many areas of the country will be changing to a winter blend of fuel which may also alleviate the condition."

 

 

sure .....

 

if you live in a state that has ethanol in its fuel, just try to find a pump without it.

 

I don't by that excuse.

 

nipper

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Right on, if the area requires ethanol in the gasoline it will be hard to find gasoline without it....except maybe race fuel?

 

Race fuel is mostly alchohol around here at 8.00 a gallon.

 

Maybe we fill up in NJ, spend a small fortune in tolls?

 

nipper

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hehe, or go up to Canada, I don't think they require ethanol in the gasoline! Maybe some people are running E20 or higher in their PZEV's and that's what soob is talking about?

 

One of the key non lead octane ingredients is toluene.

 

The Sunoco 94 stuff has lots of it, not to mention alcohol to suppress co.

 

Unburned toluene makes benzene which is carcinogenic.

 

You know that whiff of rubber like smell you get when you start most vehicles cold.

 

The 06 impreza has none of it. It is the cleanest vehicle upon startup I have yet to personally experience.

 

It's as if it is storing it away until it's at full temp?

 

Still I still miss the old wide open throttle turns it all off obd1.

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