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Why does prius have less emissions in CA

4762 Views 8 Replies 6 Participants Last post by  mrv
I visited the EPA website today and discovered that a Prius in CA has 1/5th of the emissions of a Prius sold in the rest of the country. :shock: I suspected that this was due to the availibility of cleaner fuel in CA but on the EPA website it was indicated that these vehicles are not available outside CA and few other states. Does anyone know what might be different in these cars? Is it just cleaner fuel?
:? Thanks, Ray
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I'll be anxious to hear what others say. I was under the impression that the Pruis passes "50 state emissions" and therefore, there is no difference in the vehicles themselves. I am a CA resident, but obviously I am clueless to what this is about.
I read somewhere that the emissions statement, not the actual emissions, is what differs for CA. Either that, or the cleaner fuel which CA requires, and is supposed to be phased in elsewhere as well.
Since the Prius has a good vapor control system to reduce evaporative losses and the ICE shuts off when you stop, especially in temperate climates like Kalifornia, emissions are ESTIMATED to be reduced by the mentioned amount due to the average time on the highway when the car is actually parked. See also, gridlock.

IT is the same vehicle. Actual emissions are most likely NOT different from the same car in another state. Warranty varies due to state variations in clean air restrictions but a US Prius is a US Prius. Unlike my California version Dodge Ram Turbo Diesel which is unike the same vehicle in 49 other states.

I don't doubt the reporter's reading comprehension, just the accuracey of information compared.

:D Pat :D
The Prius when sold as new is the same in all 50 states.

However, California has some labeling conventions that are not available at the federal level. In CA and the northeastern states that have adopted the CA emissions standards, there is a classification level for the Prius that is cleaner than at the federal level.

Also, California has slightly cleaner (lower sulfur) fuel, so the emissions systems (catalytic converter mostly) doesn't get as poisoned over its lifetime (works for longer) as compared to the other states that do not use that fuel.

It's been that way since the first Prius was sold in the US... They all start out the same, but those operated with CA fuel will end out being cleaner than elsewhere.
Hi All:

___I just want to add a thing or two that is not directly related but somewhat It is the lower sulfur fuel available in California that gives the Prius and just about any modern day automobile a cleaner emissions rating and actual lower emissions then in many other states. With that, not only will the entire country have available to it < 30 ppm sulfur fuel by 2006, many can purchase LS fuel today even outside of California. If you have a BP/Amoco near you, their Premium Ultimate is LS in many larger sized towns and city locations. Those in MN. and upper WI. have the ability to purchase low sulfur and low benzene fuel from their local Holiday station. You will see it labeled as Blue Planet. Blue Planets web site should help explain what it is all about I am not saying purchase Bp/Amoco Ultimate as it is a lot more expensive then regular unleaded or Blue Planet gasoline but if you want to clean the air in your locale that much more, low sulfur fuel is the way to do it in all of your automobiles including the Prius without so much as using a different station if LS fuel is available to you.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:14wn5k35][email protected][/email:14wn5k35]
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I concur with Michelle and Wayne. When I bought mine a couple years ago, I was also surprised to see the Prius listed with two different ratings: one for CA and New England, the other for the rest of the US. So, I emailed the EPA and asked for clarification.

I received a response from an EPA scientist who told me there is only one Prius for sale in the US, the only difference is the SULEV rating isn't recognized by most of the states, so the EPA has to list the same car (tested with the same low sulfur gas) twice for purely political reasons. You can consider your vehicle to be SULEV-rated regardless of your location in the US, because your perception of the Prius test results is not affected by state law!

Note: the emissions rating is based on the projected emissions at 120,000 or 150,000 miles. If you are not using low sulfur gas, your catalytic converter will become less effective over time, and your emissions will be higher than SULEV at 120,000 miles.

BP/Amoco Ultimate is low sulfur in some cities, including the following US cities: Arlington, Asheville, Atlanta, Baltimore, Birmingham, Cedar Rapids, Charlotte, Chesapeake, Chicago, Cleveland, Columbus, Denver, Des Moines, Detroit, Flint, Gary, Green Bay, Greensboro, Indianapolis, Lansing, Madison, Memphis, Milwaukee, Nashville, Norfolk, Omaha, Orlando, Peoria, Philadelphia, Portland, Quad Cities, Raleigh/Durham, Richmond, Rockford, Seattle, Sioux Falls, St. Louis, Minneapolis, St. Paul, Virginia Beach and Washington DC. (Go to and search on "clean cities programme" for details of other countries.) Holiday / Blue Planet is always low sulfur and is available in Minnesota and northwestern Wisconsin. Other choices may exist, but I'm not aware of them. However, the EPA has mandated phase-in of low sulfur gas by 2006.

I also emailed somebody in the Wisconsin Dept of Natural Resources to try to find a listing of sulfur content in my local gasolines. He said they don't have such a database, but he pointed out that E10 (gasoline blended with 10% ethanol) is inherently lower sulfur, and this is sold throughout the Milwaukee metro area. For comparison: "normal" gas has upwards of 300-500 parts per million of sulfur, E10 has around 150 ppm, and BP "low sulfur" has less than 30 ppm.

So, I buy low-sulfur whenever I can find it, expecting that it will become easier to find as 2006 approaches, and I feel better knowing my emissions will stay SULEV longer.

Douglas (2002 Silver, Wauwatosa, Wisconsin, USA)
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Thank you all for your replies. I suspected that the fuel difference was a primary factor but the wording on the website about availability of these vehicles outside CA etc. was misleading. The different labeling is kind of crazy. It seams as if the EPA should make some adjustments to their system. I checked the emissions on my F150 and it appears to have about 30 times the emissions of the Prius and 30% of the MPG. I borrowed my clients' Prius and drove the 61 mile round trip commute, including a two hour wait at home to let the car cool down. The computer said 53 MPG for the round trip, so I'mthinking my mileage will probably range around 50 for my style of driving.
Again thanks,
low sulfur trade-off

while waiting for the change to low-sulfur fuel in 2007, you have to figure out what to do right now...

Most of the stations that sell the low-sulfur fuel (if they're in your area) only sell it on the "premium" higher-octane gasoline.

On the Prius, you'll get lower MPG using the higher-octane fuels, and you're more likely to get a check-engine light (usually an engine-misfire code).

But, the low-sulfur fuels will help the longevity of your car's emissions system...

So, what do you choose? I guess it's a personal decision as to what you consider to be the lesser of two evils...
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