Impossibly low emissions?

Discussion in 'General Motoring' started by shoppa, May 4, 2005.

  1. shoppa

    shoppa Guest

    My wife's 1992 Saturn SL1 was recently run through the treadmill
    emissions test for Maryland, and they give us a printout with the
    results.

    The good new is, we passed easily.

    My question is: are these readings unusually/impossibly low?

    HC: 0.009 gpm
    CO: 0.219 gpm
    NOx: 0.021 gpm

    These are all at like one percent of the allowable amount. Cow orkers
    with similarly old cars seem to be passing the tests with 20-50% of the
    allowable amount, and this makes me wonder if any exhaust was even
    coming out of the tailpipe of our car! (Maybe a leak, or maybe they
    did the test wrong, or...?)

    The car is low mileage and has been well maintained and even a few
    emissions-related things changed over the years (PCV, Canister Purge
    Solenoid) in response to check engine codes.

    Tim.
     
    shoppa, May 4, 2005
    #1
  2. shoppa

    Shep Guest

    Looks like the decimal points are off.
     
    Shep, May 4, 2005
    #2
  3. shoppa

    Mike Walsh Guest

    I have seen several vehicles, including one of my own, with emissions so low that they register zero. I have seen it in Palm Beach county when they did emission testing and also when I lived in Maryland and they had only idle testing.
    The key is to have the engine and catalytic converter warmed up and the spark plugs clean. When one of my cars had zero emissions it was after I had been driving on the highway and I pulled into a testing station when there was no line. My sister had a Chevy astro van that failed the emission test here in Florida. It failed after she had driven a short distance from her workplace to the testing station. I knew it should have passed since I had recently tuned it up. I told her to drive it on the highway to get it warned up and get it tested again. Much to my surprise it not only passed but the emission reading were all zero.
     
    Mike Walsh, May 4, 2005
    #3
  4. shoppa

    mjt Guest

    () scribbled:
    my recent inspection, which they said did really good:
    (Texas inspection)
    Standard Current Reading
    HC (ppm) 179 41
    CO (%) 2.22 0.01
    CO2 (%) 14.6
    O2 (%) 0.0
    Nox (ppm) 1161 273
    Dilution (%) >6.0 14.6

    this is a '90 Trooper v6(Chevy engine), 198k miles !
     
    mjt, May 5, 2005
    #4
  5. shoppa

    M. Cantera Guest

    Emissons tests are mostly bullshit as cars are already pretty clean if
    they are in tune. In the beginning, the tests only weed out way out
    way out of tune cars in most situations with the exeptions of cars
    that are tuned to maximize gas mileage (such cars run lean and thus
    have high NOx volumes.




    Grams per mile? This is a conversion. Probe measures ppm.
    This may be high. Indication is that you are running rich and the
    catalitic is cleaning up the unburned HC that is coming out the tail
    pipe
    This is too low, again, your car is running rich. I have run cars
    that passed witn 1550 ppm at 25 mph with the limit set at 1668 pm for
    the test. The car was running 26 miles per gallon. Retuned to a
    richer mix on the following test, the mileage dropped to 24 mph with a
    slight increse in hc leves. I leaned it out again. With gas prices
    the way they are, I like to get the extra 10 %. If they want clean
    air, confiscate barbara treissand's private jet.
    Don't worry, the EPA will be reducing the limits in the near future.
     
    M. Cantera, May 5, 2005
    #5
  6. I agree. All those extra (and unnecessary) trips everyone has to take to
    the emission inspection stations probably generate more pollution and waste
    more fuel than catching the <1% of cars that fail. It's a job creation
    scam.
     
    James C. Reeves, May 5, 2005
    #6
  7. shoppa

    ed Guest

    What the heck is GPM? I've heard of PPM but not GPM. Maybe the decimals are
    right for whatever the heck GPM is.
     
    ed, May 5, 2005
    #7
  8. grams maby????
     
    Kevin Bottorff, May 5, 2005
    #8
  9. It appears your state like some others read pollutants in gpm, grams per
    million instead of ppm parts per million. It makes the amounts look much
    smaller but is more realistic representation of comparative sizes.
     
    Van&Joan Hada, May 5, 2005
    #9
  10. shoppa

    shoppa Guest

    gpm, grams per million

    Actually, grams per mile. I don't think my vehicle has any idle
    testing required, it's all dynamometer testing.

    Tim.
     
    shoppa, May 5, 2005
    #10
  11. shoppa

    mjt Guest

    () scribbled:
    .... Texas tests that way (dyno) too, at two different RPM settings.
    (but in Texas, the reports are in PPM or % - see my other post in this thread)
     
    mjt, May 5, 2005
    #11
  12. shoppa

    Steve Guest

    My guess would be "Grams Per Mile."
     
    Steve, May 5, 2005
    #12
  13. GPM = grams per mile, not "grams per million". GPM (more properly
    abbreviated g/mi) is how the Federal emissions certification tests are set
    up.
     
    Daniel J. Stern, May 6, 2005
    #13
  14. shoppa

    aarcuda69062 Guest

    GPM= grams per mile.
    The actual mass of the pollutant in question is measured over a
    distance. Usually measured with a "flame ionization detector,"
    which is fairly expensive.
    PPM= parts per million, percentage is the same thing at a
    different scale. Usually measured with a "non-dispersive
    infrared test cell," which is fairly cheap. PPM equates to how
    many bubbles are in a bar of soap since you can have an
    absolutely filthy reading, but if you dilute it with an air pump
    or a pulse air system, it will appear much cleaner. PPM and
    percentages do have great use when used for diagnostic purposes,
    but this is because all five gasses are compared against each
    other in order to determine whether the mixture and combustion
    efficiency are correct.
     
    aarcuda69062, May 6, 2005
    #14
  15. shoppa

    Napalm Heart Guest

    What's a cow orker? Sounds like it might be illegal under bestiality
    laws! ;+)
     
    Napalm Heart, May 6, 2005
    #15
  16. I'm with you -- there's something cockeyed about the decimal place or
    the instrument or the test procedure, one. The only other
    explanation would be a massive exhaust leak upstream of the tailpipe,
    something that should be trivial to either identify or rule out.

    Not that a well-kept 1992 Saturn isn't a nice little car, but the
    numbers quoted to you are better than a recent-model
    Ultra-Low-Emissions Vehicle, and in fact are in or near the Super-ULEV
    realm that is occupied mostly by hybrids (see for instance
    http://www.cleancarcampaign.org/emissions.shtml or
    http://www.cars.com/carsapp/nationa...tures/mvp/vpedia/vehicle_emissions_popup.tmpl).


    Cheers,
    --Joe
     
    Ad absurdum per aspera, May 6, 2005
    #16
  17. shoppa

    John S. Guest

    "Emissons tests are mostly bullshit as cars are already pretty clean if
    they are in tune."

    I disagree. If you don't have some sort of policing of pollution
    standards then there is no incentive for drivers to keep their cars in
    tune and sensors and converters working. Are you going to depend on
    voluntary compliance..."I promise to make sure my car is kept running
    right..."

    I think the standards should be tightened for older cars, and if they
    fail and can't be repaired then they should be removed from the road.
    No paying $100.00 in repairs then going on.
     
    John S., May 7, 2005
    #17

  18. Well, why not? That's what the present administration does for industry.
    Oh? And what data do you have to support your litle belief here? A '77
    Caprice you saw two weeks ago, belching smoke? The "common knowledge" that
    old cars are all a bunch of gross polluters? You were scared by a '73
    Mustang when you were small? Please elucidate.
     
    Daniel J. Stern, May 8, 2005
    #18
  19. shoppa

    Don Stauffer Guest

    That is sure true. In fact, even with laws, look at commercial
    operators. Some of the Diesel trucks around here are WAY overdue for
    maintainance. Owners just don't car. I suspect the fine for excess
    emissions may be less than the cost of a tuneup on these big rigs. Or
    else they are just gambling that they won't get caught. We have opacity
    laws here, and still the trucks spew out stuff that literally blocks out
    the sun sometimes.
     
    Don Stauffer, May 8, 2005
    #19
  20. shoppa

    Steve Guest

    Well, fortunately you're not in charge. I have no problem holding older
    cars TO THE STANDARDS THEY WERE BUILT TO. But its just stupid to tighten
    the requirement on them, especially when over 90% of all automotive
    pollution comes from cars less than 10 years old. Its a numbers game-
    there are so few old cars on the road that they just DO NOT contribute
    to the total pollution in any measurable way at all. And most of them do
    run relatively clean, because they're well-cared-for collector cars.
     
    Steve, May 9, 2005
    #20
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