Talk:Catalytic converter/Archive 2

Negative aspects
I have gone through and copyedited the Negative aspects section, for it was poorly written and improperly used very outdated sources to support present-tense assertions. More work is needed on this section; catalytic converters have not spoiled vehicle performance and economy nor started fires for many years. —Scheinwerfermann T&middot;C 04:07, 7 July 2009 (UTC)
 * Sure. Would you like to cite more recent sources proving the ever-more-complex recent catalytic converter designs no longer create backpressure? Nevard (talk) 04:55, 7 July 2009 (UTC)
 * Certainly every piece of the exhaust system creates some flow restriction — every bend in the pipe, every muffler, every catalyst. Modern designs pose substantially less restriction, to the point of likely insignificance, than early designs, and that's what needs to be conveyed. The text you inserted is a very good start in that direction, and appears to cite a rather sound investigation of the matter, though the magazine itself may be somewhat questionable. The tested Civic made 147 hp with its stock decade-old converter, and 152 hp with no converter at all. A difference of 5 in 152 is around 3%. We'd need more data to know whether this is statistically significant or within the range of variance from one dyno pull to the next, but in any event it's certainly not substantial, and that's the point we seem to agree on. I've removed the text about "…without additional tuning to take advantage of the higher flow", because that is conjecture based on unfounded speculation ("probably…") in the cited magazine article, and Wikipedia isn't a crystal ball. —Scheinwerfermann T&middot;C 14:26, 8 July 2009 (UTC)
 * You do know that current engines are designed to work with a certain level of back pressure, and that they are less efficient without it? UrbanTerrorist (talk) 02:02, 18 September 2011 (UTC)

It would be nice to have at least links to the chemical information of how the cataylsts in catalytic converters work, probably something involving electron donation or something. —Preceding unsigned comment added by 209.6.159.47 (talk) 02:34, 9 August 2009 (UTC)
 * Since there isn't any such information you won't get this. Even using an Electron Microscope it is impossible to tell exactly how the catalytic reaction works. UrbanTerrorist (talk) 02:02, 18 September 2011 (UTC)

Clarification?
Do I understand this article correctly? Catalytic converters reduce "noxious tailpipe emissions" (which I assume means localized air pollution), but increase greenhouse gas emissions which is the biggest emissions problem the world faces right now? --JHP (talk) 01:08, 23 August 2009 (UTC)
 * No, you don't understand the article right. Catalytic Converters do not increase greenhouse gas emissions, they are greenhouse gas neutral. Carbon Monoxide converts to Carbon Dioxide naturally in the atmosphere. It just happens faster in the converter, in seconds rather than in weeks. UrbanTerrorist (talk) 02:06, 18 September 2011 (UTC)

Platinium and rhodium emission
The french version of the article has a long section on the long-term problems associated with these metals. Here is a study on the concentration of these metals in Germany over 10 years. There are more sources on the french page, but no links. I'm not sure what should be done concerning this subjet, yet I'm feeling this is relevant to the article. I'm not sure the french version is worth translating either, as it's long and not very straight to the point. 84.226.239.19 (talk) 17:57, 24 November 2009 (UTC)
 * The manufacturers have been doing something about this for years because of the costs of the materials. They've been building more efficient converters which use less precious metals. They've also been working on producing longer lasting converters, which keeps less heavy metals out of the atmosphere. As to what should be done, its simple. Buy an electric car. Then you won't have to worry about having a catalytic converter on your car, will you? UrbanTerrorist (talk) 02:10, 18 September 2011 (UTC)

Moved to talk pending citation: US DoC 2008 report
Please provide citation. For all we know, this may be just a subtle verisimilitude test. As of today (2010-06-01), googling this report title in quotes yields no results except this article. Not saying it's fake, just saying we need verification. — ¾-10 23:51, 1 June 2010 (UTC)


 * I agree with your comment: "Odd that googling the alleged report title in quotes yields nothing but this page". When I added the tag to the article, I commented my edit: "I can't find this at: http://www.commerce.gov/search/node/emission - needs citation", which is a link to a search of commerce.gov, that got me no results.
 * On reflection, a far better step on my part would have been to move it here as you did.
 * I was hoping the editor who posted it might pop back with details of the location of the report. At the least, we need sight of this "report" before re-adding this.


 * I did correct 12 spelling mistakes and 4 grammatical errors in the paragraph as added, though - so at least it will be easier to discuss :) -- Begoon (talk) 00:03, 2 June 2010 (UTC)


 * No worries, your course of action was good, too. Same as I might have done except that the content of the paragraph happened to tingle my "possible BS" detector enough to make me consider moving it here. Main thing is that, thanks to you, it didn't persist without a tag. I agree that the editor who added it is welcome to come back and prove me wrong anytime (re "BS"). Cheers, — ¾-10 01:06, 2 June 2010 (UTC)

Rise in cost of vehicle

The US Department of Commerce has estimated, according to a 2008 report titled "Increase in Vehicle Cost Due to Implementation of Emission Standards", that catalytic converters add as much as $1200 on to the sticker price of a vehicle. The same report also stated that EPA required equipment, including catalytic converters, cost somewhere between 15% to 20% of the sticker price of a new vehicle. As an example, if the MSRP of a vehicle is $20,000 then 20% ($4000) of the MSRP price is due to EPA emission standards. Not only is there a rise in the cost of a purchase of a new vehicle, but also an increase in the cost of gasoline over the life time of the car. Catalytic converters limit the airflow of exhaust through the exhaust system making the system less fuel efficent. The EPA has estimated the loss of fuel efficiency by 5% per gallon. That is, a vehicle burns 5% more fuel to travel the same distance with a converter than it would without.

This is a fake report. There have been rumors of it wandering around the internet for the last couple of years. If you call the Department of Commerce they will tell you it doesn't exist. Even though the DOC will tell you that, websites still list it. People just don't bother to pick up the phone and call the government. All you have to do is ask... UrbanTerrorist (talk) 02:23, 18 September 2011 (UTC)

Withdrawal of ZDDP
An IP editor,, added the following statement to the article, at the end of the first paragraph dealing with converter poisoning:

''The preceding two sentences are not correct. While phosphorous from ZDDP is undesirable from a cataylst longevity perspective - ZDDP is still the most effective antiwear additive for gasoline and diesel engines, and has been limited, not withdrawn.''

I have replaced it with a Citation Needed tag and moved it to the talk page, for discussion. I don't have time to follow this up but hope that someone else will. --Athol Mullen (talk) 02:18, 7 November 2010 (UTC)

Increase/decrease
Is it correct in the first sentence where it says a catalytic converter is a "device used to increase the toxicity of emissions"? It feels like it should be reducing, not increasing the toxicity of emissions. —Preceding unsigned comment added by Redheadoboe (talk • contribs) 17:15, 10 November 2010 (UTC)


 * You're correct; that was only vandalism. On Wikipedia, usually when you see something screwy like that, it's only because someone vandalized the article recently. You can also check out the "history" page and not only pinpoint the vandal edit but also undo it. I encourage anyone to give it a go! — ¾-10 01:49, 16 November 2010 (UTC)