Auto gas octane rating?

[The_Eric]

Hey guys, just got a new weed eater and wanted to use some auto gas from the local airport (non ethanol and hoping longer shelf life) but can't seem to come up a solid answer as it's octane.

It's labeled as 75% auto fuel and 25% 100ll. If it was blended with a base 85 octane fuel, then it would just barely meet the minimum 89 octane requirement... but I can't be sure.

The guy at the airport didn't know, but was guessing 87? My pilot friend didn't know either since he only uses 100ll.

Any input?

 

[Bandito440]

How often does their tank get emptied and filled? I'd much rather buy fresh gas from a high-volume station than some unknown blend from an airport. http://pure-gas.org lists 185 stations in Iowa that ethanol-free gasoline. Just buy enough for the summer and give it a shot of Marine Sta-Bil.

 

[The_Eric]

Supposedly they move a fair bit of auto gas...


edit: Whether you realize it or not, you provided the answer!

I clicked on the IA link on the website and it shows my airport (Boone), it's fuels and their octane. In this case 90 and 100. So it looks like I'm good to go.

Thank you for posting the link!

 

[Oldmoparguy1]

Originally Posted By: The_Eric
Supposedly they move a fair bit of auto gas...


edit: Whether you realize it or not, you provided the answer!

I clicked on the IA link on the website and it shows my airport (Boone), it's fuels and their octane. In this case 90 and 100. So it looks like I'm good to go.

Thank you for posting the link!


That's good info. The 100ll will keep the af fresh for a long time. I know a guy that uses no-E farm fuel and adds 10% 100ll, Works fine in his tractor and his old Aeronca antique airplane.

 

[horse123]

Why are you so determined to use airplane fuel? Do you know how many thousands of small engines were used on whatever cheap pump gas people could find and are still running after 20, 30 years?

 

[SwampSurvivor]

I think he is trying to avoid using ethanol gas.

 

[skyactiv]

You can remove ethanol from gas if your willing but you need to start with 91-93 octane as the process drops the octane about 3 points. You add water to gas, shake and drain. Use a milk jug and open the bottle upside down. You will see the water/ethanol on the bottom with the gas on top. Drain till the water/ethanol is out of the jug. It works. It's hazardous to do and check the laws on it.

 

[A_Harman]

Originally Posted By: skyactiv
You can remove ethanol from gas if your willing but you need to start with 91-93 octane as the process drops the octane about 3 points. You add water to gas, shake and drain. Use a milk jug and open the bottle upside down. You will see the water/ethanol on the bottom with the gas on top. Drain till the water/ethanol is out of the jug. It works. It's hazardous to do and check the laws on it.


Is there a YouTube video showing this?

 

[A_Harman]

Originally Posted By: horse123
Why are you so determined to use airplane fuel? Do you know how many thousands of small engines were used on whatever cheap pump gas people could find and are still running after 20, 30 years?


The OP said he was running a weedeater. 2-stroke engines don't last long on fuel containing ethanol. Using regular pump gas ruined two 2-stroke hedge trimmers for me over a period of 4 years.

 

[4wheeldog]

Originally Posted By: A_Harman

Is there a YouTube video showing this?


I ain't hard enough for a Youtube. Try this:
http://goldwingdocs.com/forum/viewtopic.php?t=14679

 

[horse123]

All things with engines sold in the US in the last 10 years have been tested with E10 which is the maximum you would find in normal pump gas.

 

[The_Eric]

Originally Posted By: A_Harman
Originally Posted By: horse123
Why are you so determined to use airplane fuel? Do you know how many thousands of small engines were used on whatever cheap pump gas people could find and are still running after 20, 30 years?


The OP said he was running a weedeater. 2-stroke engines don't last long on fuel containing ethanol. Using regular pump gas ruined two 2-stroke hedge trimmers for me over a period of 4 years.



Correct. While I certainly don't mind using an ethanol blended fuel in pretty much everything else, I tend to stay away from it in little 2 cycles. Also, like I said, this fuel will need to keep longer than I typically require of fuel. The combination of no ethanol and alkylates in aviation fuel should do the trick.

After some thinking, I'm not so certain that the mogas offered at our airport is 90 octane, so I went back and bought a gallon of straight 100LL to blend in. Assuming an 87 octane for the mogas and 100 for the LL, I should end up with 93.5 octane and plenty of alkylates.

 

[HerrStig]

Originally Posted By: A_Harman
Originally Posted By: skyactiv
You can remove ethanol from gas if your willing but you need to start with 91-93 octane as the process drops the octane about 3 points. You add water to gas, shake and drain. Use a milk jug and open the bottle upside down. You will see the water/ethanol on the bottom with the gas on top. Drain till the water/ethanol is out of the jug. It works. It's hazardous to do and check the laws on it.


Is there a YouTube video showing this?
Yes, it ends with a small mushroom cloud. The guy holding the camera won't be down for breakfast.

 

[HerrStig]

Originally Posted By: horse123
All things with engines sold in the US in the last 10 years have been tested with E10 which is the maximum you would find in normal pump gas.
Some of us care for our OPE and it'a more than 10 years old.