AVgas, Best Long Term Fuel Storage w/o Drawbacks?

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AVgas, otherwise known as 100LL, or aviation gas - what is the bottom line about using it in our small engines, generators and mowers?

I know it has not been discussed in a while. Near me, are two small airports, the first one won't let you even pump it without an aircraft. The second one, will let me pump it, in my 5 gallon jerry can for (what I thought was a good price) of $3.85/gallon. From what I understand:

* 1) Using the 100 octane, AVgas, I can expect faster startups and better throttle response.

* 2) Using AVgas, I can expect the shelf life of this gas to last several YEARS, not a couple of months, like "car pump gas".

* 3) When AVgas dries, it leaves no varnish like residue behind, thus making carburetor cleaning & replacement, a thing of the past (almost).

* 4) No ethanol involved, so it is less likely to attract water, while sitting in the gas tank over the winter.


Questions:

* 5) Can I mix AV gas with automotive gas and use it in my small engines? How about using leftover AVgas in my vehicles?

* 6) Will I have any issues with small engine plugs fouling?


I have Lawn Boy mowers, a cold blooded Honda EU3000is generator and 2 cycle string trimmer. Generator doesn't want too keep running off the choke, until fully warm. Lawn Boys can be temperamental upon cold startup. Will AVgas improve their performance, or improve their fuel consumption?
 
Originally Posted By: Best F100

* 1) Using the 100 octane, AVgas, I can expect faster startups and better throttle response.



Thats not how octane works.

Using 100 in a small engine that is designed to run on 85 wont give you better performance unless you bump the compression or make other changes.
 
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There is a product called Sta-Bil that is supposed to help with storage of fuel for a long time. I use it in portable generator, winter for lawn mowers and etc

The 100LL will hurt your pocket book for sure. If you are worried about ethanol in your gas simply seek out a station that pumps non-ethanol gas meant for autos.

Or simply run the engine dry and store dry like some people do to prevent gumming of fuel. Good luck
 
TN has plenty of ethanol free pumps. Use that and buy some sealed cans to store it in.
 
Just buy Ethanol free and use Pri-G in it.

AV 100LL says low lead but its actually a ton of lead, not good.
2 grams per gallon IIRC.
 
If you mix it with car gas you compromise what you're trying to do.

Run your *whatever* out of gas, throw 1/2 cup of avgas in, then run it out of *that*.

The lead isn't great, it bridges spark plugs and builds up gunk in other parts of the engine as well.
 
The father-in-law has a briggs brand genny, brother-n-law borrowed it for like two years.
B-I-L just abused and neglected it.

Long story short, the f-i-l live 2.5miles from mid size private airport.
So 100LL is in use now and 18gal in storage.


The kohler liteplant gets 100ll, race/pump, or premix pump. but this thing dates to the 1950's.



the av gas is awesome, the lead not so much.
 
Originally Posted By: Rand
Just buy Ethanol free and use Pri-G in it.

AV 100LL says low lead but its actually a ton of lead, not good.
2 grams per gallon IIRC.


I think the content is stated at 2.2-2.4 TEL/gal.

It's actually in line with or a bit below leaded pump gas(when it was still available).

Classic cars designed for high octane leaded fuel love the stuff. 100LL is roughly 96 R+M/2, which is a bit high for a motor gas but not out of line for high compression engines. That's not to mention that if you haven't put hardened seats in, your valves will thank you.

With that said, I think your average small engine will do just as well on 90 REC or plain 87 ethanol free. Both are available with a bit of hunting, and overall are easier to buy than AVGAS.
 
FWIW, aviation fuel is subject to more quality controls than the average run of automobile gasoline. That said, how many car and truck drivers can with certainty say they've received 'bad' gas from any but hole-in-the-wall operations?

100LL is not adjusted by season; airplanes travel too quickly through large climate changes to customize fuel by locale and season.

To help prevent vapor lock issues, avgas has a lower vapor pressure than is generally found in automotive fuel. Okay in the summer, but cold-weather starting may be compromised because the avgas doesn't vaporize as easily as one might wish.

Taking lead out of automobile fuel was a wonderful thing. Some of us are old enough to remember short spark plug life, exhaust valves that didn't always last as long as hoped, and oil contamination that absolutely contributed to the build up of deposits in engines.

Avgas does seem to deteriorate at a slower rate than the typical automobile fuel. That may be of occasional benefit, but probably more by accident than intention. That is, someone who knows a car is going to be parked for a year (or some other long period of time) can take some advance precautions to prevent fuel fouling. But I'd sure hate to go back leaded fuel for everything just in case I might sometime leave a gas engine unused for many months.

Over the past many years I've used unleaded auto fuel in three different airplanes that had engines originally certified to use 80/87 avgas. Routine instances of plug fouling simply disappeared, and hundreds of hours of engine operation did not show unexpected damage to valves or valve seats.

With luck, a reasonable lead-free fuel is coming in the near future for general aviation. I can hardly wait.
 
I use Avgas regularly in my OPE. It lasts forever, really. However, it can dry out certain neoprene components, such as the seals on a fuel shut off valve. Even so, I have far fewer problems using 100LL than with pump gas. Especially in equipment that just sits unused all year long. I have some 100LL that is well over 10 years old and is still perfect.
 
The big drawback IMO to storing avgas is you can't use it in your vehicle if you need to. If you're going to go through the trouble you want the most versatility. If you're using real deal jerry cans with an airtight seal regular gas is going to store for a long time.
 
Originally Posted By: CrAlt
Originally Posted By: Best F100

* 1) Using the 100 octane, AVgas, I can expect faster startups and better throttle response.



Thats not how octane works.

Using 100 in a small engine that is designed to run on 85 wont give you better performance unless you bump the compression or make other changes.


And it will actually be the opposite effect, it will be harder to start.


Octane rating is a resistance to detonation, in resisting the detonation, you are also resisting the desired burn.
 
There's also some evidence that in small high rpm motors it can limit performance, doesn't want to burn fast enough for them. Chainsaws, dirtbikes, generally other two stroke motors.
 
and this issue with health. If you have kids around when running your ope, gennys, etc -do not- use avgas. It is a hazard to childern with no actual safe lowest exposure.

Then, do not put it in anything with a catalyzer. It will be gone basically immediately.
 
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