AVIATION GAS (AVGAS)

[swat]

The LL in 100LL AVGAS stands for low lead, meaning reduced lead content. Basically AVGAS is the same as Auto gas, and is teted for moisture content to prevent freezing a high flight levels. There is no ethanol in ANY AVGAS, but if you are putting higher octane gas in an auto engine that is not designed for the higher compression requirements, you are just throwing money down the drain. In aircraft, we can use a highr octane fuel if a lower octane fuel is not available, but NEVER a lower octane than the engine was designed for. The different dye in AVGAS is used to visually determine what ocgane rating is actually being pumped into the aircraft. There are many piston engined aircraft that now have a supplemental type certificate (STC) issued by the FAA for that particular iarcraft, that allows you to burn auto gas in the aircraft, and many owners are taking advantage of that to dramatically save over the price of AVGAS, which is usually double or more the cost of auto gas.

[wesk]

I think I made it quite clear in the other post that the 100LL was to be diluted with the auto gas. It is not being used at 100 octane and it's main purpose is to introduce longer stoarge life to the fuel in the tank. The extra cost is about the same as buying gallons of stabil a year and the results are better. There's no need to make such an alarmist announcement.

The term "low lead" is a relative term. In avgas the lead content was significantly higher than auto gas for many years. Hence 100LL is a reduced lead version of standard 100 and still contains more lead than most auto gas products of the 60's and 70's.

Auto gas STC's (Special FAA approvals for use) are dieing a slow death in the aviation world. They have become useless since they do not allow the use of any auto gas that contains ethanol and alcohol products which are needed to dry up water contamination are not allowed to be used in them.
The approvals for auto gas being used in aircraft is limited to lower HP rated engines. Also the industry experience with aircraft using auto gas approvals is higher incidences of vapor lock in warm weather and a much greater contamination with moisture in colder weather along with damage to system rubber parts.

It is also the position of all aircraft engine manufacturers and the majority of CRS (FAA Certified Repair Stations) engine overhaul shops that they do not warranty their engines or cylinder kits when they are operated with auto gas.

That leaves the issue of price. Each individual that wishes to consider the use of avgas 100LL in place of stabil to improve the storage life of their fuel can do the arithmetic for themselves in their economic geographic areas.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[Jim]

NOTICE: I don't know anything about AVGAS other than
that's what was put in my Cessna 150 when, since I figured
my young bod was going to 'Nam, I'd rather see the sights
from up high, I learned to fly. Anyhoo, here in Darkest Arkansas,
if you use gasoline on which the road tax hasn't been paid, you
can get in trouble with the authorities, though I suppose a gallon
or two for the M-vehicles most likely would be ignored. I do know
if I get five gallons of 'off-road' diesel, I get charged sales tax.
Since most states have their own laws on this, your milage may
vary.

Jim in Darkest Arkansas
(looking for 2-5 inches of global
warming on Monday)

[wesk]

I doubt the revenue agents are hanging at the airport waiting to follow you home and photograph you pouring that blue dyed gas into your MV.

I carried it home for years for my aircraft, my yard tractors (where it helps replace the lead in the gas they were used to) and my MV's and early CJ5. It doesn't see much if any road use. When you figure over 80% of the roadable fleet is post smog equipped a person would have to have a nut loose to pour any 100LL into his late model ride.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[oldairplanenut]

I just drive the Jeep right up to the pump at the airport. There are so many federal, state, local, and airport taxes tacked on to the stuff that I don't feel wrong about doing it. Nobody has ever made any remarks to me either.