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)