What's lead got to do with it? | Fuel Tips

They do make a really good point about the difficulty of rating oxygenated fuels.  
     I'm found several sources that E85 has 100 octane and almost as many that claim 110 octane. 
 if we toss a little lead into E85 does that affect only the gas portion or the whole gallon?  

frenchyd said:

 if we toss a little lead into E85 does that affect only the gas portion or the whole gallon?  

It actually makes the knock resistance worse, having tried some blends of E98 and various race fuels to make "E85" legal fuels.

It's interesting to not address the health effects of lead in fuel- I'm sure that it was removed for that purpose as well? That is a question, to be clear. 

On a personal level, I have a riding friend who insists on fueling his bikes with 100LL from the local airport. It is so obnoxious (and noxious) to ride behind him. It was also shockingly stanky at the vintage races I attended a couple weeks ago. I dunno, count me out of the leaded fuel camp.

frenchyd said:

     I'm found several sources that E85 has 100 octane and almost as many that claim 110 octane. 

IIRC the 110 rating is for pure ethanol.  E85 is a blend with gasoline and the allowable blend ratio can be anywhere from 50% ethanol up to 85%.  Obviously the percentage is going to affect the rating substantially, as is the rating of the gasoline it's mixed with.

Teh E36 M3 said:

It's interesting to not address the health effects of lead in fuel- I'm sure that it was removed for that purpose as well? That is a question, to be clear. 

AIUI, no, the direct health effects of aerosol lead were not really a factor in the legislation.  Those effects are recognized now (there has been some interesting research correlating violent crime rates with the usage of TEL ~ 20 years before, when the people committing those violent crimes were babies), but at the time it was being driven by the goal of reducing smog and thus needing fuel that didn't destroy catalytic converters.

The general aviation industry really needs to get with the 70s and certify engines that can run on unleaded fuels.

codrus (Forum Supporter) said:

Teh E36 M3 said:

It's interesting to not address the health effects of lead in fuel- I'm sure that it was removed for that purpose as well? That is a question, to be clear. 

AIUI, no, the direct health effects of aerosol lead were not really a factor in the legislation.  Those effects are recognized now (there has been some interesting research correlating violent crime rates with the usage of TEL ~ 20 years before, when the people committing those violent crimes were babies), but at the time it was being driven by the goal of reducing smog and thus needing fuel that didn't destroy catalytic converters.

The general aviation industry really needs to get with the 70s and certify engines that can run on unleaded fuels.

 

Wow- I really didn't know that it was driven from a smog perspective and not general health.  Also- I'm a pilot (but a commercial pilot) who is just dipping his toe into GA, god yes do they need to get with the times. I'm shocked that the GA industry (such as it is) hasn't embraced water cooled engines, like large displacement aluminum LS motors, for replacement and new construction. Crazy. Also, more importantly, stop with the 100ll.

codrus (Forum Supporter) said:

frenchyd said:

     I'm found several sources that E85 has 100 octane and almost as many that claim 110 octane. 

IIRC the 110 rating is for pure ethanol.  E85 is a blend with gasoline and the allowable blend ratio can be anywhere from 50% ethanol up to 85%.  Obviously the percentage is going to affect the rating substantially, as is the rating of the gasoline it's mixed with.

 

Unless you buy E85 in cans or drums from racing fuel supplies.  There it's always 85% ethanol  without the absorbed water pump fuel has and the gas isn't whatever  but can be  real racing gasoline.  You pay about $1 a gallon more  but the quality is worth it plus it's about what you'd pay for pump grade 87 octane.  

Why Did Leaded Fuels Go Away?

To meet the emissions standards introduced in the 1970s, car manufacturers began installing catalytic converters. Lead oxide, a byproduct of combustion, leaves a residue on catalytic converters, rendering them useless. Lead as a fuel additive quickly fell from favor.

Leaves a residue on catalytic converters...oh, and also poisons every square millimeter of our biosphere, that was kind of an issue:

https://www.mentalfloss.com/article/94569/clair-patterson-scientist-who-determined-age-earth-and-then-saved-it

Teh E36 M3 said:

codrus (Forum Supporter) said:

Teh E36 M3 said:

It's interesting to not address the health effects of lead in fuel- I'm sure that it was removed for that purpose as well? That is a question, to be clear. 

AIUI, no, the direct health effects of aerosol lead were not really a factor in the legislation.  Those effects are recognized now (there has been some interesting research correlating violent crime rates with the usage of TEL ~ 20 years before, when the people committing those violent crimes were babies), but at the time it was being driven by the goal of reducing smog and thus needing fuel that didn't destroy catalytic converters.

The general aviation industry really needs to get with the 70s and certify engines that can run on unleaded fuels.

 

Wow- I really didn't know that it was driven from a smog perspective and not general health.  Also- I'm a pilot (but a commercial pilot) who is just dipping his toe into GA, god yes do they need to get with the times. I'm shocked that the GA industry (such as it is) hasn't embraced water cooled engines, like large displacement aluminum LS motors, for replacement and new construction. Crazy. Also, more importantly, stop with the 100ll.

The volume of engines used in general aviation is too tiny to certify  new engines.   Plus there are some die hards who insist reliability comes from old magneto's  not modern electronics.  
Who's going to pay for the fight required to get the entrenched out?  
  Modern composition airframes and wings water cooled engines. Etc the sky's could get as crowded as the highways are. 

Xylene is 117 octane, toluene is 114 octane.

You can get a gallon of xylene at home depot for $22. Add that to four gallons of 92 pump gas and you should be around 97-98 octane. Without lead.