[MBZ] Continued off topic

[David Brodbeck]

andrew strasfogel wrote:
> I took my well-maintained 1970 280SE 3.5 coupe that I drive less than
> weekly on average through DC motor vehicles inspection last Friday.
> Despite the age of the car, they ran it through the tailpipe emissions
> check inadvertently.  The vehicle actually passed with the following
> test results:  HC 204 ppm (limit 1250); CO 3.30 % (limit 9.00), and
> CO2 11.6% (limit not specified).    Are these numbers good, great or
> so-so?
>   

Well, for comparison to a "modern" car, here are some fresh results from 
my '95 Ford Crown Vic's WA emissions test:
Idle: HC 12 ppm, CO 0%, CO+CO2 14.7%
25 mph: HC 18 ppm, CO 0.06%, CO+CO 15.36 %.
They messed up and only tested one tailpipe, though, so I'm not sure how 
accurate those numbers are.

My '89 VW Cabriolet:
Idle: HC 87 ppm, CO 0.27%, CO+CO2 12.97%
25 mph: HC 84 ppm, CO 0.31%, CO+CO2 15.61%
The Cabriolet had a miss at idle at the time and desperately needed a 
tuneup, which probably accounts for some of the high HC number.  (Here 
it pays to test *before* you do any work, because you can get a waiver 
if you spend more than a certain amount trying to fix a car that fails.)

I believe the CO+CO2 number is just to make sure the exhaust isn't being 
diluted by leaks; in the WA test, it has to be at least 6%.