Grams per mile to ppm

[rick-l]

I just got my car Emissions Inspected on a dyno in Missouri. They give you a printout with grams per mile. Anyone know a conversion to Parts Per Million so I can compare these readings with my fuel injection literature?

[Hugh R]

There really isn't a conversion. Your comparing two different units of measure. PPM, is literally that how many parts (molecules) of hydrocarbons or NO2 are present per million parts (molecules) of air. There is a formula to convert ppm to milligrams per cubic meter of air, that formula is ppm= mg/m3(cubed) x 24.45/molecular weight of the material. But, you have to assume the NOx emissions are as NO2, or the hydrocarbons are as methane. If you knew the cubic feet per minute of exhaust, and the exhaust temp. you might be able to figure out ppm, but I'm still not sure that you could compare it to PPM at the injectors.

[rick-l]

This is the response I got from gateway clean air. Didn't answer the question


Dear Mr. xxxx;

The Gateway Clean Air Program utilizes a variety of test methods approved by
the state of Missouri and EPA in administering vehicle emissions tests.

The tests conducted at the permanent stations register results in grams per
mile. We also offer a completely different type of emissions test known as
RapidScreen. With RapidScreen, vehicles are evaluated as they drive by a
stationary van. The exhaust plumage is collected in an ultraviolet/infrared
beam and tested for compliance. The results are registered in parts per
million. Through RapidScreen we are able to identify and exempt the
cleanest of the vehicles on the roadways.

The two tests, permanent stations and RapidScreen, are not an
apples-to-apples comparison. Both are used to effectively evaluate the
integrity of a vehicle's emissions system.

Sincerely,

Robert xxxx
Public Relations Manager

-----Original Message-----
From: No-Email-Given@nowhere.none [mailto:No-Email-Given@nowhere.none]
Sent: Wednesday, April 28, 2004 10:06 AM
To: gcap@mo.etest.com
Subject: GCAP comment form

[Hugh R]

Agreed, grams per mile on a dyno and using a uv/ir (fourier transfer infrared) on the highway to measure concentrations coming out of the tail pipe are two completely different things.

[HarryD]

Originally posted by rick-l
This is the response I got from gateway clean air. Didn't answer the question


Dear Mr. xxxx;

The Gateway Clean Air Program utilizes a variety of test methods approved by
the state of Missouri and EPA in administering vehicle emissions tests.

The tests conducted at the permanent stations register results in grams per
mile. We also offer a completely different type of emissions test known as
RapidScreen. With RapidScreen, vehicles are evaluated as they drive by a
stationary van. The exhaust plumage is collected in an ultraviolet/infrared
beam and tested for compliance. The results are registered in parts per
million. Through RapidScreen we are able to identify and exempt the
cleanest of the vehicles on the roadways.

The two tests, permanent stations and RapidScreen, are not an
apples-to-apples comparison. Both are used to effectively evaluate the
integrity of a vehicle's emissions system.

Sincerely,

Robert xxxx
Public Relations Manager

-----Original Message-----
From: No-Email-Given@nowhere.none [mailto:No-Email-Given@nowhere.none]
Sent: Wednesday, April 28, 2004 10:06 AM
To: gcap@mo.etest.com
Subject: GCAP comment form

Scary

So this allows them to test your car whether you agree to the test or not. I would think there would be a legal challenge due to the nature of how/when the test is performed. By bringing your car tot he test center, you have agreed to be bound to the test rersults. If they remotely sniff you and then try to attempt enforcement, I would think there are a number of challenges to the test that could be raised.

[rick-l]

If you knew the cubic feet per minute of exhaust, and the exhaust temp. you might be able to figure out ppm, but I'm still not sure that you could compare it to PPM at the injectors.

The gas analyzer they use must measure parts per million. Why do they give me this bogus grams per mile crap instead of something that you can compare to manufacturer standards and the literature about Fuel Injection? Since no one has chimed in that this is a standard unit of measure I would assume it is an arbitrary number based on a made up standard (liters of exhaust per mile).

s it just me or is everyone insane?

[Randy Webb]

Harry, Just as you can be held to consent to a blood EtOH sniffer or other test by driving on a publi hwy, you can surely be held to impliedly consent to having the car tested. Don't hod your breath on any challenges to this.

Rick, Why do you want to know ppm? If it is imp. to you then you will need to ask somebody besides the low level secretaries or techs in the agency. You could always do a public records request if it is that critical to you. Many states can charge for that. See an attorney in your state if you want to go that route.

[HarryD]

Originally posted by Randy Webb
Harry, Just as you can be held to consent to a blood EtOH sniffer or other test by driving on a publi hwy, you can surely be held to impliedly consent to having the car tested. Don't hod your breath on any challenges to this.

Rick, Why do you want to know ppm? If it is imp. to you then you will need to ask somebody besides the low level secretaries or techs in the agency. You could always do a public records request if it is that critical to you. Many states can charge for that. See an attorney in your state if you want to go that route.

Randy,

In the case of EtOH, they can pull you over and ask you to take the test. You can refuse and incur that penalty or you can comply and live with that result. I doubt they can test you from far away and use that in evidence.

Basically, you have the option to refuse the test but there is a consequence. Why should this be different?

[dhoward]

No enforcement (at this time ).
What it does is allow you to NOT have to present your vehicle for testing at the dyno station. Effectively, after your vehicle has been sniffed by a roadside station 3 times, You will get a mailing stating that you have passed the emissions inspection and can recieve the sticker by mail.
I took my truck there yesterday and got a 'fast pass'. No sniff, just checked the OBDII for codes. Still took 45 minutes. I'll take the drive-through any day...
As far as real gas analysis, these guys aren't exactly rocket scientists (brain surgeons, nuclear physicists, insert other smart guy here.....)

[rick-l]

Originally posted by Randy Webb
Rick, Why do you want to know ppm? If it is imp. to you then you will need to ask somebody besides the low level secretaries or techs in the agency. You could always do a public records request if it is that critical to you. Many states can charge for that. See an attorney in your state if you want to go that route.

It's not that important to me but I would like to compare my car to federal and California standards. I would also like to see where my car is running on the combustion chemistry charts(the no-cat one). Looking at this it appears the state has an arbitrary pollution scale (grams per mile) that they can make say whatever they want.

[Matt77Euro27]

Everyone else is insane.

[rick-l]

Originally posted by dhoward
I took my truck there yesterday and got a 'fast pass'. No sniff, just checked the OBDII for codes. Still took 45 minutes. I'll take the drive-through any day...

I think they look at the OBDII readiness monitors. I think there is a market for a device that takes SAE J1850 serial data and filters it so it says what they want to see.

[rick-l]

Originally posted by Matt77Euro27
Everyone else is insane.

That's what I thought and they're all starting to piss me off.

[rick-l]

ITEM 2!!!!!!
The smog sponges (first descrip not appropriate) aged my 88 by 28,000 miles when they inspected it (Einstien wrote the mileage down wrong).

Does CARFAX get data from vehicle smog inspections in Misourri?

[Randy Webb]

Harry, I would look at the infra-red photo case for a guy in Oregon growing maryjane -- the real question is what is your expectation of privacy. That is the legal issue behind your protection from govt. "searches". My guess - and I only do envl law (and only when I have to, as I'd much rathr be doing science) is that emitting something from your car's exhaust pipe is not going to give you much of a privacy expectation.

But we can wait and see - somebody is bound to challenge it sooner or later and then the courts will decide...

On the conversion - I'd send an Email to EPA using their web site. I'd phrase it as "I want to voluntarily keep my car as clean as possible even tho I don't have to" and also as "my car club wants to be good guys" so their overworked staff will be more likely to try and find a good answer for you. Remember you have to get past the outer guards (secretaries, receptionists, low level "tech support" morons who know less aobut computers than my dog....) to get info in any organization.

[johnsjmc]

I believe the standard was changed from ppm to grams per mile back in the 70s .A highly tuned small engine like the 911 was dirtier than a lazy huge American engine when looking at exhaust percentages in ppm. The change to grams per mile will consider the output of the vehicle and will actually favor the small engine . Tuning equipment might still be using ppm . I don,t know a conversion but a passing engine /car combination can probably be assumed to be well tuned from an emission standpoint, perhaps not for max horsepower.