]]]]]]]]]  DIRTY-CAR TUNEUPS BEAT OXY-FUELS BY A MILE    [[[[[[[[
                      By Donald H. Stedman               (2/6/90)
           Mr. Stedman is  a professor of chemistry 
                    at the University of Denver.
    [From The Wall Street Journal, 6 February 1990, p. A18:3]

          [Kindly uploaded by Freeman 10602PANC]

   Every   version  of   the  Clean   Air  Act   currently  under
consideration  contains  provisions   for  mandating  alternative
fuels.  Cost estimates reviewed  for the Business Roundtable vary
from $40 million to several  billion dollars a year.  Millions of
dollars are already being spent  in Arizona, Colorado, Nevada and
New Mexico on the mandated use of oxygenated fuels in vehicles as
a carbon-monoxide control measure.
   Yet the same Environmental  Protection Agency database used to
justify the use of oxygenated fuels shows there's a better way to
control carbon-monoxide  emissions: Tuning up  the small minority
of dirty cars  is twice as  effective as --  and much cheaper and
simpler than -- using oxygenated fuels in the entire fleet.
   At the University  of Denver, we have  analyzed the studies of
oxygenated  fuel  on  vehicle  emissions  in  the  EPA's national
database and other  available studies.  The  results from all the
studies are striking in their similarity.
   Half the carbon  monoxide emitted comes from  about 10% of the
vehicles  tested.  Half  the improvement  in the  per-mile carbon
monoxide emissions attributed to  fuel oxygenation comes from the
same 10% of the fleet.  If  those few vehicles were to have their
emissions systems tuned  up to equal  the average of  the rest of
the fleet,  the emissions  improvement would  be almost  twice as
large as  the improvement obtained  by using  oxygenated fuel for
the entire fleet.
   As an example, an EPA study of 84 vehicles published last year
showed that 80  of them emitted  a total of  397 pounds of carbon
monoxide, while  the dirtiest four  emitted 338  pounds [85.1% of
the base].  When the entire fleet was put on oxygenated fuel, the
total emissions  reduction was  203 pounds  [57.9% of  the base],
with the dirty  four contributing 107  pounds of that improvement
[52.7% of the improvement].  If the dirty four were tuned to emit
the average of the rest of the  fleet, they would emit a total of
20 pounds  -- a  318-pound reduction  in emissions  [80.1% of the
base] from the tuning up of only four vehicles.
   Oxygenated fuels  cost more,  decrease gas  mileage and damage
vehicle  components.  Therefore,  a  program that  identifies and
mandates  tuneups  for  just  the  gross  polluters  offers major
advantages.
   An actual tuneup study of 10 vehicles was conducted in 1978 by
the  Colorado  Department  of Health.   The  10  vehicles studied
emitted a  total of  434 pounds  of carbon  monoxide using normal
gasoline.  When 10%  ethanol fuels were  used, the fleet emission
dropped to  335 pounds  [77.2% of the  base].  When  only the two
dirtiest cars  were tuned up,  and the normal  fuel retained, the
fleet emissions dropped to 294 pounds [67.7% of base].
   Last  summer,  there   was  a  widely   publicized  rally  for
methanol-fueled vehicles.  It was  not widely publicized that the
emissions from those specially prepared vehicles were essentially
identical  to those  from any  new vehicle  that could  have been
bought from any  showroom nationwide.  It  is tempting to suggest
that the problem is not dirty fuels, but dirty cars.
   The University of Denver has developed a remote sensing device
that can detect carbon-monoxide  emissions from passing vehicles.
The  results of  more than  250,000  measurements agree  with the
statistics from the government testing programs; namely, half the
carbon monoxide emitted comes from about 10% of the vehicles.  We
now have  a tool  to identify  the gross  polluters very cheaply.
All  the data  show  conclusively that  a  good tuneup  of  a few
vehicles  would  be  more  cost  effective  than  mandating  less
efficient fuels for everyone.
   Mandated oxygenated-fuel  programs cost an  estimated $500 per
ton of carbon monoxide removed, according to a study prepared for
the EPA last September by  RCG/Hagler, Bailly Inc.  (The estimate
does not include  a realistic assessment of  gas mileage lost, or
any  estimate  of  vehicle-parts  damage.)   Annual  exhaust-pipe
inspection and maintenance  programs cost more  than $780 per ton
of carbon  monoxide removed.  A  program based  on remote sensing
and tuneups of  the gross polluters would  cost, I estimate, only
$40 per ton.
   All the studies  point to the  cost-benefit advantages of this
program.  The choice is clear.

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