From: mark@wdcwdc.sps.mot.com (Mark Shaw)
Subject: Re: Old Car Emissions (Update)
Organization: Motorola Western MCU Design Center, Chandler Arizona
Date: Mon, 5 Oct 1992 21:51:16 GMT

 (Bruce R. Miller) writes:
|> > |> As someone else has said, type-b dogs provide parts for type-a babies!
|> > |> But, we shouldn't overlook the fact that many type-B dogs really are
|> > |> dogs, but they are Paid for and the people who own and drive them, and in
|> > |> many cases have no alterternative transportation,  will be suffering in
|> > |> a very real way from bans on old cars, or whatever. 

|> > Let me paraphrase your comments:
|> > 
|> > It's great to have all those poor disadvantaged people out there trying to
|> > keep those old wrecks running, so we can buy the parts we need when we need
|> > them!

|> WHOA!! That's what you call paraphrasing???
|> Maybe I'm partly to blame by not responding in the right place and
|> leaving the context unclear.
|> 
|> Someone classified type-b dogs and claimed, to the effect, that noone
|> would miss them.  I just wanted to make the point that there are poor
|> people who use & need these for transportation and have _NO_ chance of
|> buying a new car, clean or not.
|> Other than ephemeral things like "heritage" and Hobbies, _THESE_ are the
|> people that would be hurt most by any plan to smash old cars.

Sorry Bruce, this "politically correct" concept of saving old cars for
the poor to use is a real hot button for me.   If we are truly concerned
with the welfare of the poor, we would find a way to get them reasonable
transportation.  I sure that this topic is not a part of alt.auto.antique
charter, so I don't think we should use it as a defense for something that
also helps us.   Our arguments for saving old cars should stand on their own.
I didn't mean to condemn you for making the comment, I just spiced it up
a bit to get the point across :-)

|> Another point;  Much is made of the fact that old cars make 10 times the
|> pollution of a new car.  Your article "Old Car Emmissions" gave the data:
|>   "Pre-70 425cid, uncontrolled, tuned 12mpg -> 1.71 pounds/12mile trip
|>    post-82 any closed-loop lambda           -> 0.13 pounds/12mile trip"
|> 
|> That's pretty dramatic I grant you.  It may even be true.
|> But are you claiming that a 425" engine is representative of all "old
|> cars"?
|> Since this (apparently) leads to the 50% figure, it's worth examining.

I agree that a 425cid engine was not common for the 60's, the above data
was to indicate the folly in using older %CO testing.  It did not clearly
demonstrate the effects of engine size/fuel economy.

A more realistic view would be to compare the CAFE data and emission test
standards.   The NHTSA data I have for CAFE for vehicles manufactured only
goes back to '74.  Estimating pre-1968 as slightly better than 1974:

YEAR         pre-1968      1974        1982         1991
Domestic     14?           13.2        25.0         27.3  mpg
Import       25?           22.2        31.1         29.7  mpg
Total Fleet  16?           14.2        26.6         28.2  mpg

If you use my CO pollution estimation factors for a 25 mile trip:

YEAR         pre-1968      1974        1982         1991
Domestic     3.21          1.89        0.25         0.23
Import       1.80          1.13        0.20         0.21
Total        2.81          1.76        0.24         0.22

So on average 1974 cars put out 8 times more than 1982 and later cars.
And pre-1968 cars put out about 13 times more than 1982 and later cars.
These numbers for CO track pretty close to the emissions standards:

YEAR         pre-1968      1974        1982         1991
CO           102**         28*         3.4          3.4    grams/mile
HC           10.6**        3.0*        0.41         0.41   grams/mile
NOx          4.1**         3.1*        1.0          1.0    grams/mile

The 1974 data is an estimate by the EPA to correct for the variations
in test methods.  The pre-68 data is an estimate by the MVMA.  It is
interesting to note that their estimate is more pessimistic than mine.
So taking my more optimistic ratios of 13:1 and 8:1 and looking at
number of old vehicles reported by R.L.Polk and compiled by MVMA:

Total Number of vehicles in use 1990:      123,276,000      100.0%
Vehicles in use 1990, built 1982-1990:      79,157,000       64.2%
Vehicles in use 1990, built 1976-1981:      32,399,000       26.3%
Vehicles in use 1990, built before 1976:    11,720,000        9.5%         

If we make the really simple assumption that these cars all drive
similar missions (miles to/from work) and that anything pre-1982
is 8 times worse that post-1981 then there are 35.8% of the vehicles
puting out 8x:

64.2 x 1 =  64.2
35.8 x 8 = 286.4  82% of total!

Pretty gross, huh?  Now we can discuss the lower mileage use of the
older cars, but they would have to be used on average about 1/4
as much as new cars to still account for 50% of pollution.

Spooky numbers, I agree.   The real numbers that shock me are the
large number of older cars.  In 1970 there were only 6.2% of the
cars were more than 11 years old.  By 1990 that percentage jumped
to 20.3% were more than 11 years old.  People are just keeping
their cars longer (both rich and poor alike).

Mark
Newsgroups: alt.autos.antique