Replies to This Discussion

Permalink Reply by Andrea K on November 18, 2008 at 6:27pm

Oh, it's not just that I see the fumes, I can also smell the foul stench coming out of the muffler. I ride a lot, and I'm just surprised how often I end up behind cars belching out more than their fair share of pollution.

• ▶ Reply

Permalink Reply by Todd Allen on November 21, 2008 at 11:14am

Your nose doesn't lie. We get bad air quality on hot humid summer days and cold winter ones. The mix of pollution products differ between summer and winter but both are noxious.

Emissions testing is done on hot engines. And engines are tuned for best performance when hot. When cold there are a lot more incomplete combustion products. Complete combustion of a hydrocarbon such as gasoline without impurities or additives results in carbon dioxide and water, both very breathable in reasonable quantities. Incomplete combustion results in a toxic brew that is bad to breath.

Cold catalytic converters don't do much to clean up the exhaust either. So the much nastier exhaust passes through unremediated. In the winter it takes longer for everything to warm up and run properly. When drivers do a series of short trips running errands about the city in winter the percentage of time the engine spends running in its cold dirty state can be quite large.

There are other factors that add to the problem. Many folks let their cars sit and idle for long periods of time to warm up. But at idle cars warm up very slowly which greatly increases the time spent running cold and the total amount of emissions produced. And minor engine tuning problems such as an incorrect idle speed or an improper air/fuel ratio have an even greater impact on emissions when an engine is cold.



h3 said:

I doubt anything has significantly changed about emissions standards, Andrea.
They say Gasoline has little smell but it's the additives that stink-- quite likely a bunch more additives are being used for winter.
Otherwise, proliferation of remote starters seems to be way on the rise; I see many idling each morning for so long I suspect they were either started by accident of someone went back to bed and forgot (yes they disgust me but that's another story). Could be that these folks are destroying their catalytic converters with excess heat buildup. The converter's job is to be really really hot and cause the remaining unburned hydrocarbons that make it that far to burn the rest of the way. But get it too hot and the platinum coating melts off and leaves it useless.

• ▶ Reply

Permalink Reply by Dan P. on November 21, 2008 at 12:39pm

"Is there anything the local bike groups here can do to help pass legislation that will try to get these polluting cars fixed and/or off the road?"

"Rep. Henry A. Waxman (D-CA) made history yesterday by challenging and defeating the sitting chairman of the House energy and commerce committee, Rep. John Dingell (D-MI) by a 137 to 122 vote of the full Democratic caucus. This committee is immensely important, with jurisdiction over a wide variety of domestic matters. Waxman is a close ally of Speaker Nancy Pelosi, who is also from California. Both of them want much tougher laws to reduce global warming, something Barack Obama also promised. Dingell, in contrast, was much more concerned with protecting the automobile industry than with protecting the environment. Waxman's counterpart in the Senate is yet another Californian, Sen. Barbara Boxer (D-CA). With most of the power concerning the environment in hands of Waxman, Boxer, Pelosi, and Obama, it is likely that global warming will be addressed very quickly in the new administration, with the views of the Californians playing a dominant role." -- www.electoral-vote.com, aka. andrew tenemabaum, 11/21/08

If anything. This will help introduce a new level of pro-environment from the top down. For once.

• ▶ Reply