AV Gas

[toolmaker]

My local Stihl dealer sells AV gas at his shop. He gets it at the airport and claims it is 103LL.

I completely understand the benefits of non-ethanol fuels.

The high octane (103)
Is it truly beneficial?
Or is it a farce?

 

[IyaMan]

Your dealer is an idiot if he's putting that in a saw, or just trying to rip you off.

This topic is currently being discussed here:

https://www.arboristsite.com/community/threads/sunoco-race-fuel.340912/

And its probably time to find a new dealer...

 

[huskihl]

No need. I’d search for the freshest lowest octane fuel I could find that was ethanol free. Usually it’s 89-95 octane

 

[Canyon Angler]

The high octane (103)
Is it truly beneficial?

Only if you're getting pre-ignition / knocking without it.

 

[ironman_gq]

The Octane is actually detrimental, the lead is detrimental, about all it has going for it is a long shelf life.

 

[U&A]

No need. I’d search for the freshest lowest octane fuel I could find that was ethanol free. Usually it’s 89-95 octane

I agree,

Anything more is not necessary or beneficial IMO.

89 ethanol free for me


Sent while firmly grasping my redline lubed RAM [emoji231]

 

[stihl86]

Only if you're getting pre-ignition / knocking without it.

…..and if you are getting pre-ignition or detonation with 87/89, you should investigate why. First, before anything else.

 

[RTK]

My local Stihl dealer sells AV gas at his shop. He gets it at the airport and claims it is 103LL.

It comes as 100 octane low lead (100LL), no such thing as 103LL at any airport that I know of.

 

[sb47]

It comes as 100 octane low lead (100LL), no such thing as 103LL at any airport that I know of.

That is what my local airport sells is 100 octane.

 

[trappermike]

In the old days av gas was the way to go,hi-octane. The stuff to buy was called 100/130,real high octane.It smelled fantastic,and my muslecar and motorcycle loved it. but some time long ago they stopped making it period. The stuff today may not be even as good as premium pump gas. I cooked a piston in my snowmobile trying the modern stuff,but the guy at the airport tried to tell me it was low octane stuff,so he was right. You gotta buy car race gas,but why you'd need it in a 2-stroke I don't know. Todays premium pump gas will make any hot 2-stroke happy,except I would never used methanol blended gas in a race saw.

 

[RTK]

100LL is the same as it always has been, 100 octane blue in color. It is called low lead, but not really that low in lead. The fuel almost lasts indefinitely without going bad and will not form varnish etc. I've used it in all my lawn and garden equipment for years. I never drain the fuel out in winter and they all start up when spring rolls around.

 

[trappermike]

Yes that is the 100/100 stuff that cooked my sled,it's low octane,just not hot gas.

 

[RTK]

I don’t know if the Green 100/130 is produced much anymore, maybe in small batches for older military planes. The purple 115/145 is made especially for the Reno air races I believe.

 

[wcorey]

I do like 100ll for it's stability in storage but the octane is overkill for saws and I don't like re-tuning for it or the idea of extra lead exposure.
That said there's a relatively new avgas out that is intended to replace 100ll where the octane requirements allow but it hasn't become widely accepted and so has very limited availability.
I'm in the northeast and there's only a couple small airports in this entire part of the country that sell it and closest is almost a 3 hour round trip away.
Seems to be a lot of availability in the upper midwest for some reason.
It's called Swift UL94, alkylate based, no lead and a bit lower octane with the same type of low gum stability as 100ll.
Next time I'm out that way I need to remember to bring a couple gas cans and give it a try, should be only a buck or two more than regular pump gas too.

 

[RTK]

They were supposed to come up with a lead free alternative a few years ago. Unfortunately most of the companies dropped out of the competition due to the fact it was impractical or government red tape.

 

[SteveSr]

The 100 base is pure iso-octane by chemical formula. It is pure alkylate fuel. If you add lead to it you have 100LL AV gas. If you dilute it with other fractions such as butane to lower the octane rating and add 2-stroke oil you get Moto-Mix, Tru Fuel, and similar products. The main thing going for it is shelf stability and not forming varnish or attracting water like ethanol.

BTW, your dealer IS an IDIOT for selling this stuff for O P E use. Lead exposure would be a liability along with selling a non-manufacturer approved fuel which would void any and all warranties.

 

[trappermike]

2-strokes don't normally need high octane gas,whatever high test pump stuff you can get should be good,better if you can get it without alcohol percentage.

 

[Mad Professor]

In the old days av gas was the way to go,hi-octane. The stuff to buy was called 100/130,real high octane.It smelled fantastic,and my muslecar and motorcycle loved it. but some time long ago they stopped making it period. The stuff today may not be even as good as premium pump gas. I cooked a piston in my snowmobile trying the modern stuff,but the guy at the airport tried to tell me it was low octane stuff,so he was right. You gotta buy car race gas,but why you'd need it in a 2-stroke I don't know. Todays premium pump gas will make any hot 2-stroke happy,except I would never used methanol blended gas in a race saw.

100LL has not changed in many years. That is the blue AV gas. The 130 AV gas is green. They also made 87 AV gas which was red, for real old prop planes.

I have used 100LL in 2-strokes without incident for many years now.

It does have lead which poses a health issue. Don't huff the vapor or burnt fumes, and avoid skin contact. Be careful cleaning up combustion chamber and muffler, use gloves.

100 octane is overkill for most saws and it will require a retune. But the fuel, mixed or straight up will store for years. It won't eat the rubber parts up in a saw, or leave snotty residue in the fuel system.

If you cooked a piston in your sled, don't blame 100LL.

Cars? I ran one with 12:1 CR and used both the blue and green AV gas. The green was more octane than needed even at 12:1 CR and I cut it with good pump gas. Back then Cam 2 "race car gas" was twice the price of 100LL, and didn't run any better.