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In looking on the EPA's vehicle emissions website "http://www.epa.gov/autoemissions/" I am under the impression that there is more than one level of clean when it comes to the prius and other low emission vehicles. It seems from what's on that website that the cleanest vehicles are only available in some markets (California, the Northeast) and that the cars that are sold in the rest of the country have a lower threshold for emissions standards. The EPA rates emmissions for a vehicle from 1 to 10, ten being best and 1 being worst. The Prius they say is available in the select markets of course has a rating of 10. The prius that is available in Florida (and most of the rest of the country, carries a rating of 7, which is the same as many other vehicles, both hybrid and conventional. Please respond as to the validity of this info.
 

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My understanding is that there is only one model of Prius available in the US (disregarding model years). Its list of features on the window sticker will include "50 state emissions package". However, in California (and a few New England states), it is rated SULEV (super ultra low emissions vehicle), but in the rest of the country it is rated ULEV (ultra low). This is because the gas sold in CA and NE contains less sulfur than gas sold elsewhere in the country. Therefore, any car that burns this gas will have lower sulfur dioxide emissions than a similar car burning normal gas.

So, if gas stations in your area offer low-sulfur gas, filling your tank with that will automatically turn your ULEV HEV into a SULEV HEV!

Douglas (2002 Silver, Wisconsin)
 

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Re: "So, if gas stations in your area offer low-sulfur gas, filling your tank with that will automatically turn your ULEV HEV into a SULEV HEV!"

Not at all. SULEV is simply a legal status enforced by the laws of California and a few other states. Nobody has ever posted evidence that a Prius running sulpher laden gasoline would fail the California test. It might be true or it might not. The primary reason the Prius is not classified SULEV in other states is that neither the Federal Government or the other states has such a classification.

While it's true that sulpher poisons a catalytic converter, we don't know whether this is relevant to the lifespan of a Prius since we don't know how much extra capacity was built into the Prius cat.

We do know that there's no physical distinction between a Prius delivered to Califormia and a Prius delivered to another point in the continental U.S., but there is a difference in the warrentee terms on the emissions control systems. Nobody but Toyota knows why, it might be force of habit, or it might take into account the difference in catalytic converter failure rates.

In any case, even if you carefully run only sulpher free gasoline in your Prius, if you didn't buy it in California or another state recognizing SULEV, it's not SULEV, and Toyota won't replace your cat under warrentee once the shorter non-SULEV compliant period has elapsed.

P.S. if someone besides Toyota does happen to know why, and is reading this, please post the additional information with appropriate references.

Prius: designed to be SULEV no matter where in the continental U.S. it ends up.
 

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I split the Gasohol thread into a seperate topic. Since Douglas replied to both topics in one post I have included here the part that pertains to this topic....Pete

RSnyder says the Prius is probably just as clean if you burn normal gas or low-sulfur gas, the only difference between CA and the rest of the US is that only CA recognizes the SULEV classification. However, the EPA website lists two numbers for the Prius: a "10" for CA (and NE) and a "7" for the rest of the US. "10" is the cleanest possible rating, and the ratings are given in pounds of emissions per mile traveled. It doesn't say anything about SULEV or ULEV, it just says if I drive a Prius a mile in CA, I put out many less pounds of pollution than if I drive the same car a mile elsewhere. If it's the same exact car, and if the gas doesn't make a difference, where are those extra pounds of stuff coming from?

Douglas (2002 Silver, Wisconsin)
 

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Somebody sent email to the EPA and got an involved explanation from them which was posted to the yahoo group quite a while back. You could either try to hunt down that post, or just write to them yourself. Maybe if they get the same question enough times they'll post an explanation on their site (or maybe they already have?).
 

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I am familiar with this thread, but I reviewed it just now at your suggestion. Here is a summary of the points relevant to this discussion.

In Yahoo group toyota-prius:
- In msg 39176 and 39180, Paul claims the Prius is SULEV everywhere, but other states don't recognize this rating. He posted detailed data he acquired from the EPA.
- In msg 39183, Graham contradicts, pointing out that these results were obtained using fuel only available in CA, called "CA CARB PHASE II GASOLINE (CERT)".
- In msg 39256, John claims this fuel has been available in MN for some years now.
- It was also explained in this thread that a rating such as SULEV is based on 120,000 mi data, not new car data. Any particular car may meet SULEV standards when new, but over time it will naturally degrade, and if it falls below SULEV standards before it reaches 120,000 mi, it cannot be classified as SULEV when sold. It was hypothesized that using normal sulfur gas will damage the catalytic convertor sufficiently that even if you switch your Prius to low-sulfur gas after several years of normal gas, your emissions will remain non-SULEV (unless you get a new cat). This is apparently the reason Toyota offers a longer warranty on the emissions equipment for cars operated in CA.

I did actually send an email to the EPA yesterday, asking for clarification of these issues. Particularly, I asked how I can find out where to get low-sulfur gas in my area. I would be willing to drive a moderate distance and pay extra for it. Not only would I be personally cleaner, but I would encourage gas companies that it's worth selling in my area. (Hey, those are the same reasons I bought a Prius!) No response yet, and I have no idea how responsive they are, but I will post any information they give me.

Douglas (2002 Silver, Wisconsin)
 
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