Editing Talk:2478: Alien Visitors 2

Jump to: navigation, search
Ambox notice.png Please sign your posts with ~~~~

Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision Your text
Line 19: Line 19:
 
::Does 167,000 aircraft in the USA (plus more around the world) count as “limited niche use”? Assuming a super conservative estimate of an average of only 100 hours/year/airframe and an equally conservative burn rate of 10 gal/hr, that’s 167 million gallons of leaded gasoline burned per year. See https://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=14754 for more info on the FAA’s continuing refusal to remove lead from avgas.[[Special:Contributions/172.70.110.44|172.70.110.44]] 04:46, 20 June 2021 (UTC)
 
::Does 167,000 aircraft in the USA (plus more around the world) count as “limited niche use”? Assuming a super conservative estimate of an average of only 100 hours/year/airframe and an equally conservative burn rate of 10 gal/hr, that’s 167 million gallons of leaded gasoline burned per year. See https://www.faa.gov/news/fact_sheets/news_story.cfm?newsId=14754 for more info on the FAA’s continuing refusal to remove lead from avgas.[[Special:Contributions/172.70.110.44|172.70.110.44]] 04:46, 20 June 2021 (UTC)
 
:::Considering the 276 million cars in the USA and their yearly consumption of 123.5 billion gallons of fuel, that is pretty much limited niche use, yes. [[Special:Contributions/162.158.94.232|162.158.94.232]] 14:40, 21 June 2021 (UTC)
 
:::Considering the 276 million cars in the USA and their yearly consumption of 123.5 billion gallons of fuel, that is pretty much limited niche use, yes. [[Special:Contributions/162.158.94.232|162.158.94.232]] 14:40, 21 June 2021 (UTC)
::::Classic example of a logical fallacy.  To paraphrase your assertion: “Because the market for 100LL fuel for piston aircraft is 0.1% the size as the unleaded gasoline market for automobiles, 100LL fuel for piston aircraft is a niche market” but you are comparing apples to bacon by comparing automotive unleaded gasoline to 100LL aviation fuel. Status as “niche” or “not niche” is based on sales of leaded fuel; cars run on unleaded gasoline, diesel, or electricity, and are thus irrelevant to the discussion.  I mean, why not mention how much jet-A is burned by turbine aircraft? Answer: because it’s irrelevant to the discussion.  Cars burning unleaded fuel is irrelevant to the discussion of leaded gasoline. In terms of absolute quantities, piston aircraft burn far more 100LL than anything else, and lead from those aircraft remains a significant source of lead pollution.[[Special:Contributions/172.70.114.48|172.70.114.48]] 03:59, 22 June 2021 (UTC)
 
  
 
::Although lead was originally added to gas in order to improve efficiency, it was retained in order to reduce refining expense.  After refining crude oil, you get gasoline at a variety of octanes.  The different octanes are blended to produce what you pay for (e.g. 87 for regular, 93 for premium).  Lead is an octane-boosting additive, allowing manufacturers to ship sub-standard gas (that is a little below the rated octane), adding lead to bring it up to standard.  Without lead, you need to blend in a higher proportion of higher-octane gas in order to get the required octane rating.  Which is why, back when lead was being phased out, unleaded gas cost more than leaded.  The effect of lead reducing engine knock is simply a result of the gas having a higher octane rating.  High octane gas without lead (e.g. premium) has the same effect.
 
::Although lead was originally added to gas in order to improve efficiency, it was retained in order to reduce refining expense.  After refining crude oil, you get gasoline at a variety of octanes.  The different octanes are blended to produce what you pay for (e.g. 87 for regular, 93 for premium).  Lead is an octane-boosting additive, allowing manufacturers to ship sub-standard gas (that is a little below the rated octane), adding lead to bring it up to standard.  Without lead, you need to blend in a higher proportion of higher-octane gas in order to get the required octane rating.  Which is why, back when lead was being phased out, unleaded gas cost more than leaded.  The effect of lead reducing engine knock is simply a result of the gas having a higher octane rating.  High octane gas without lead (e.g. premium) has the same effect.

Please note that all contributions to explain xkcd may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see explain xkcd:Copyrights for details). Do not submit copyrighted work without permission!

To protect the wiki against automated edit spam, we kindly ask you to solve the following CAPTCHA:

Cancel | Editing help (opens in new window)

Template used on this page: