"Over time, Mogas deteriorates faster than Avgas"

[Jay Honeck]

This from a thread in rec.aviation.owning:

> Leave unleaded mogas in your lawnmower for a year, and it
> likely won't start. Autogas lacks the stabilizer package found in
> avgas.

You know, I've heard that ever since I started using mogas in my
planes, but I've never seen a cite, nor have I *ever* noticed a
problem with unleaded gasoline in *any* of my lawn mowers, leaf
blowers, or snow blowers.

I put 'em away in the spring/winter, and start 'em up the following
winter/summer -- and away we go. Same with my Honda Goldwing -- I
top
it off, and it just sits till next year. No troubles.

Can anyone point me to anything that proves (or disproves) the "fact"
that unleaded mogas deteriorates faster than avgas?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Ron Wanttaja]

On Sat, 15 Sep 2007 13:45:13 -0700, Jay Honeck > wrote:

> This from a thread in rec.aviation.owning:
>
> > Leave unleaded mogas in your lawnmower for a year, and it
> > likely won't start. Autogas lacks the stabilizer package found in
> > avgas.
>
> You know, I've heard that ever since I started using mogas in my
> planes, but I've never seen a cite, nor have I *ever* noticed a
> problem with unleaded gasoline in *any* of my lawn mowers, leaf
> blowers, or snow blowers.
>
> I put 'em away in the spring/winter, and start 'em up the following
> winter/summer -- and away we go. Same with my Honda Goldwing -- I
> top
> it off, and it just sits till next year. No troubles.
>
> Can anyone point me to anything that proves (or disproves) the "fact"
> that unleaded mogas deteriorates faster than avgas?

One would think this provides the answer....

http://stinet.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA174091

Chevron says mogas is good for at least a year:

http://www.chevron.com/products/prodserv/fuels/bulletin/longterm_gasoline/

"Chevron gasoline can be stored for a year without deterioration when the
storage conditions are good -- a tightly closed container and moderate
temperatures."

But then, they say that same thing about Avgas:

http://www.chevron.com/products/prodserv/fuels/bulletin/aviationfuel/8_ag_perf.shtm

"Avgas that has been properly manufactured, stored, and handled should remain
stable for at least one year. "


Ron Wanttaja

[Bertie the Bunyip[_19_]]

Ron Wanttaja > wrote in
:

> On Sat, 15 Sep 2007 13:45:13 -0700, Jay Honeck >
> wrote:
>
>> This from a thread in rec.aviation.owning:
>>
>> > Leave unleaded mogas in your lawnmower for a year, and it
>> > likely won't start. Autogas lacks the stabilizer package found in
>> > avgas.
>>
>> You know, I've heard that ever since I started using mogas in my
>> planes, but I've never seen a cite, nor have I *ever* noticed a
>> problem with unleaded gasoline in *any* of my lawn mowers, leaf
>> blowers, or snow blowers.
>>
>> I put 'em away in the spring/winter, and start 'em up the following
>> winter/summer -- and away we go. Same with my Honda Goldwing -- I
>> top
>> it off, and it just sits till next year. No troubles.
>>
>> Can anyone point me to anything that proves (or disproves) the "fact"
>> that unleaded mogas deteriorates faster than avgas?
>
> One would think this provides the answer....
>
> http://stinet.dtic.mil/oai/oai?
&verb=getRecord&metadataPrefix=html&iden
> tifier=ADA174091
>
> Chevron says mogas is good for at least a year:
>
> http://www.chevron.com/products/prodserv/fuels/bulletin/longterm_gasol
i
> ne/
>
> "Chevron gasoline can be stored for a year without deterioration when
> the storage conditions are good -- a tightly closed container and
> moderate temperatures."
>

If you leave it in your airplane, it isn't stored in a tightly closed
container, though, is it? It sure isn't in mine!
I have noticed the difference and found that mogas, having sat in an
airplane for a few months, is a lot harder to get going than equivelant
Avgas in the same airpane.

Might be my own notions based on the info I'd received, but my arms
would disagree!

Also, we have a shell petro-chemical engineer in our circle and he tells
us that the aromatics in mogas evaporate more readily thuus causing the
degradation in quality.
He also gave us a very frightening ocument relating the dangers of the
chemicals in modern mogas! You don't want that stuff on you or in you!

Bertie

[Robert M. Gary]

On Sep 15, 1:45 pm, Jay Honeck > wrote:
> This from a thread in rec.aviation.owning:
>
> > Leave unleaded mogas in your lawnmower for a year, and it
> > likely won't start. Autogas lacks the stabilizer package found in
> > avgas.
>
> You know, I've heard that ever since I started using mogas in my
> planes, but I've never seen a cite, nor have I *ever* noticed a
> problem with unleaded gasoline in *any* of my lawn mowers, leaf
> blowers, or snow blowers.
>
> I put 'em away in the spring/winter, and start 'em up the following
> winter/summer -- and away we go. Same with my Honda Goldwing -- I
> top
> it off, and it just sits till next year. No troubles.
>
> Can anyone point me to anything that proves (or disproves) the "fact"
> that unleaded mogas deteriorates faster than avgas?
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993www.AlexisParkInn.com
> "Your Aviation Destination"

It depends where you live. Out here in California they put corn or
whatnot in the autogas. If you leave that stuff in your mower or weed
eater for even 30 days you'll spend the next 30 days in the shop. I've
had my current weed eater in the shop 3 times this year just to clear
out the carb due to the crappy gas. The shops recommend always running
then dry and never, ever, storing gas for me than 30 days. Even at
that you need to have the lines cleaned to remove the sludge that the
mogas creates.

-Robert

[Maxwell]

"Robert M. Gary" > wrote in message
ps.com...
>
> It depends where you live. Out here in California they put corn or
> whatnot in the autogas. If you leave that stuff in your mower or weed
> eater for even 30 days you'll spend the next 30 days in the shop. I've
> had my current weed eater in the shop 3 times this year just to clear
> out the carb due to the crappy gas. The shops recommend always running
> then dry and never, ever, storing gas for me than 30 days. Even at
> that you need to have the lines cleaned to remove the sludge that the
> mogas creates.
>

Have you tried 100LL, or racing fuel from a local speed shop? We use so
little in weed eaters and such, it might be worth the price.

[Stealth Pilot[_2_]]

On Sat, 15 Sep 2007 13:45:13 -0700, Jay Honeck >
wrote:

>This from a thread in rec.aviation.owning:
>
>> Leave unleaded mogas in your lawnmower for a year, and it
>> likely won't start. Autogas lacks the stabilizer package found in
>> avgas.
>
>You know, I've heard that ever since I started using mogas in my
>planes, but I've never seen a cite, nor have I *ever* noticed a
>problem with unleaded gasoline in *any* of my lawn mowers, leaf
>blowers, or snow blowers.
>
>I put 'em away in the spring/winter, and start 'em up the following
>winter/summer -- and away we go. Same with my Honda Goldwing -- I
>top
>it off, and it just sits till next year. No troubles.
>
>Can anyone point me to anything that proves (or disproves) the "fact"
>that unleaded mogas deteriorates faster than avgas?

in australia at least there are additives in automotive fuel that
degrade on exposure to uv light. this causes a fine flakey sediment to
settle out. this was the cause of 'dont use in aircraft' warnings in
our country.

Stealth Pilot

[Jay Honeck]

> in australia at least there are additives in automotive fuel that
> degrade on exposure to uv light. this causes a fine flakey sediment to
> settle out. this was the cause of 'dont use in aircraft' warnings in
> our country.

They *added* stuff to the gas that causes flakey sediment?

Have you got a cite for that?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Jay Honeck]

> If you leave it in your airplane, it isn't stored in a tightly closed
> container, though, is it? It sure isn't in mine!

Um, well, it's as tightly closed as any vented tank can be. Even gas
station storage tanks aren't sealed tight, or they'd be unable to
expand/contract with temperature changes.

> I have noticed the difference and found that mogas, having sat in an
> airplane for a few months, is a lot harder to get going than equivelant
> Avgas in the same airpane.

I have never noticed the slightest difference. Now, of course, I
don't let my plane sit for months, or even weeks -- but my motorcycle,
convertible, lawn mower(s), lawn blower(s) and vacuum, and snow
blower(s) ALL sit for many months, unused. No problemo starting or
running in the spring/winter.

> Also, we have a shell petro-chemical engineer in our circle and he tells
> us that the aromatics in mogas evaporate more readily thuus causing the
> degradation in quality.

Again, a cite? ANYTHING in writing, ANYWHERE about this problem with
mogas?

For ten years I've been hearing "my buddy the engineer told his
brother that..." -- and, after a decade (and over 9,000 gallons of
trouble-free mogas in our planes) I'm simply not buying it anymore
without SOME kind of evidence.

IMHO, as with so many of these things, we desperately want to believe
that gasoline that costs 25% more is really better in some tangible
way. I have seen no evidence of this, at all, over a decade of use.
That would zero, zilch, nada -- no difference.

Of course, to that end, there are STILL people out there who will pay
a premium for high-octane gasoline for their cars, despite
overwhelming evidence that this is a complete waste of money. The
oil companies just shrug their shoulders, pocket the extra dough, and
keep making commercials touting how their brand "cleans your
injectors", or some other BS.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Bertie the Bunyip[_19_]]

Jay Honeck > wrote in news:1189950184.266800.205080@
57g2000hsv.googlegroups.com:

>> If you leave it in your airplane, it isn't stored in a tightly closed
>> container, though, is it? It sure isn't in mine!
>
> Um, well, it's as tightly closed as any vented tank can be. Even gas
> station storage tanks aren't sealed tight, or they'd be unable to
> expand/contract with temperature changes.


True,. I'd be no expert on the subject anyway.
>
>> I have noticed the difference and found that mogas, having sat in an
>> airplane for a few months, is a lot harder to get going than
equivelant
>> Avgas in the same airpane.
>
> I have never noticed the slightest difference. Now, of course, I
> don't let my plane sit for months, or even weeks -- but my motorcycle,
> convertible, lawn mower(s), lawn blower(s) and vacuum, and snow
> blower(s) ALL sit for many months, unused. No problemo starting or
> running in the spring/winter.

I've noticed the opposite with mowers bikes and what not, usually after
more than six months, but they do still start (eventually) and seem to
run fine, but there must be some deterioration taking place. You only
have to let the stuff sit for a couple of years to watch it turn
completely to varnish, so surely there must be some progres made towards
that state in the interim.
>
>> Also, we have a shell petro-chemical engineer in our circle and he
tells
>> us that the aromatics in mogas evaporate more readily thuus causing
the
>> degradation in quality.
>
> Again, a cite? ANYTHING in writing, ANYWHERE about this problem with
> mogas?
>

I actually do have one somewhere. If I can't lay my hands on it in the
house here, I should be able to get a copy of it somewhere.

> For ten years I've been hearing "my buddy the engineer told his
> brother that..." -- and, after a decade (and over 9,000 gallons of
> trouble-free mogas in our planes) I'm simply not buying it anymore
> without SOME kind of evidence.

Up to you, I'm not trying to sell anything anyway..


>
> IMHO, as with so many of these things, we desperately want to believe
> that gasoline that costs 25% more is really better in some tangible
> way. I have seen no evidence of this, at all, over a decade of use.
> That would zero, zilch, nada -- no difference.
>
> Of course, to that end, there are STILL people out there who will pay
> a premium for high-octane gasoline for their cars, despite
> overwhelming evidence that this is a complete waste of money. The
> oil companies just shrug their shoulders, pocket the extra dough, and
> keep making commercials touting how their brand "cleans your
> injectors", or some other BS.


Well, octane has nothing to do with quality. In fact, any octane present
in fuel has little to do with it's octane rating. Engine octane
requiements are arrived at by feeding an engine a fuel consisting of a
given octane-heptane mixture. The point at which the increaed addition
of octane stops detonation in a specific engine dictates it's octane
rating and the burn rating of the fuel for that specific engine. Lead
was added to boost the octane rating of fuel, but it's not the only way
to increase a fuel's resistance to detonation, thus the newer low lead
fuels we have nowadays.
There are legit additives that keep our engine cleaner nowadays, and
there is no doubt that thye work. Anyone who can remember having to pull
a head off at 50,000 miles for a "de-coke" or whatever you would like to
call scraping the **** off the tops of pistons and heads can attest to
that!

Meanwhile, here's a source I just discovered (but haven't read through
completely) just for fun.

http://www.faqs.org/faqs/autos/gasoline-faq/part2/preamble.html

Some interesting stuff in there.. He refutes what my guy told me about
lead free being more toxic than the old leaded fuels, but of course, as
this guy states in this document, that's not true globally (and my guy
works for Shell outside the US).
Also, he seems to be talking about the resulting product out of ytour
tailpipe, which the document I was talking about agrees with this
osition, merely staing that raw unburnt fuel is more toxic than the old
stuff (IIRC it was particularly dangerous for women and their
reproductive systems) I mentioned that merely because as a group, we, as
pilots tend to get more of the stuff splashed on us than most people (I
certainly do, anyway)
He also explains much more concisely than I have, what exactly an octane
rating is..


Bertie

[Ron Wanttaja]

On Sun, 16 Sep 2007 21:14:12 +0800, Stealth Pilot
> wrote:

> in australia at least there are additives in automotive fuel that
> degrade on exposure to uv light.

A lot of transparent fuel tanks in Oz, are there? :-)

Ron Wanttaja

[Jim Burns]

Again from Chevron
http://www.chevron.com/products/prodserv/fuels/bulletin/motorgas/3_refining-testing/pg5.asp
sites the internationally recognized formulation standards which include
specs for stability and gum solvent content.

We own two 10k gal gasoline tanks, one for 89 oct unleaded and one for 89
oct unleaded plus lube additive for the old truck valve trains. Each of
those tanks sit less than 1/2 full for 5-6 months before I buy a load to
split between them, usually in the spring. When less than 1/2 full, those
tanks have a lot of surface area exposed allowing evaporation of the gas's
lightest components, not to mention water condensation. We see no problems
with gasoline that has been stored for 5-6 months. We've got a fleet of
over 50 gas powered trucks ranging from pickups to midsized bulk trucks that
range in age from the 1960's to current production. The trucks that don't
get used year around start and run fine each spring with the fuel that's
left in the tanks from when we put them away each fall. No fouled plugs,
not fuel system problems.

Our fuel rep said that you "might" see some performance degradation in high
compression/high horsepower engines from the fuel oxidizing slightly while
it sat, but as long as it meets the current manufacturing standards, it
should be fine. He said that most problems reported are from users that
have contaminated gas that has all but totally evaporated in their fuel
systems. The contaminates remain behind then get flushed into carb jets and
needle valves or fuel injectors by fuel from the tank. He said that
contamination is a much bigger problem than age.

We buy unbranded fuel strictly on price. Sometimes it contains ethanol,
sometimes it doesn't, sometimes we end up with a branded product, most of
the time we don't. We never notice a difference. Our guy wasn't pushing
any special brand or formulation. YMMV.

I noted that several of the posts mentioned small engines. Are these 4
strokes burning straight gas or 2 strokes burning blended gas/oil mixtures?

Jim



"Jay Honeck" > wrote in message
ps.com...
> This from a thread in rec.aviation.owning:
>
>> Leave unleaded mogas in your lawnmower for a year, and it
>> likely won't start. Autogas lacks the stabilizer package found in
>> avgas.
>
> You know, I've heard that ever since I started using mogas in my
> planes, but I've never seen a cite, nor have I *ever* noticed a
> problem with unleaded gasoline in *any* of my lawn mowers, leaf
> blowers, or snow blowers.
>
> I put 'em away in the spring/winter, and start 'em up the following
> winter/summer -- and away we go. Same with my Honda Goldwing -- I
> top
> it off, and it just sits till next year. No troubles.
>
> Can anyone point me to anything that proves (or disproves) the "fact"
> that unleaded mogas deteriorates faster than avgas?
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>

[Jay Honeck]

> I noted that several of the posts mentioned small engines. Are these 4
> strokes burning straight gas or 2 strokes burning blended gas/oil mixtures?

In my case, it's both. I've got an annoying mix of 2- and 4-stroke
gasoline tools -- but none of them show any kind of problems running
"old" gasoline.

Thanks for the information about your experiences. I'm sure gasoline
EVENTUALLY goes "bad", due to evaporation and water contamination --
but I think it's highly unlikely that "aviation gasoline" is any
different than "auto gasoline" in this regard.

I simply don't believe that the oil companies put any extra money into
production of aviation gasoline, especially when they sell such a
tiny, insignificant amount of it. Does anyone (besides me) think that
oil companies would keep the two formulas as close to identical as
possible, with the exception of lead, in the interest of cost
savings?

Personally, I think this is just another busted aviation myth. But
I'm sure there will always be those who believe that the $4.40/gallon
stuff is better than the $2.89/gallon stuff, just like there are those
who swear by Marvel Mystery Oil, flying on "the step", and fear
stalling when turning the same direction as the wind.

(Hey -- anyone want to debate "shock cooling" now that it's getting
cold out?)

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Morgans[_2_]]

"Jay Honeck" <> wrote

> I have never noticed the slightest difference. Now, of course, I
> don't let my plane sit for months, or even weeks -- but my motorcycle,
> convertible, lawn mower(s), lawn blower(s) and vacuum, and snow
> blower(s) ALL sit for many months, unused. No problemo starting or
> running in the spring/winter.
>
>> Also, we have a shell petro-chemical engineer in our circle and he tells
>> us that the aromatics in mogas evaporate more readily thuus causing the
>> degradation in quality.
>
> Again, a cite? ANYTHING in writing, ANYWHERE about this problem with
> mogas?
>
You must use your stuff deep enough into the season, and fire it up early
enough in the season to avoid any problems.

There have been too many people say that they have had problems with their
small engines to discount it.'

Add me to the list. I recently got out my 6 1/2 HP Briggs overhead valve
push mower, and it would not start when I put fresh gas in.

I took the carb apart, and it is complete trash. I don't even think
cleaning it would help. It will require a new carb.

It has been about 1 1/2 years since I last used it. It is JUNK , now.

Would av gas be any better? I don't know. I do believe that you had better
keep mogas less than a year in your machines, though.
--
Jim in NC

[Jim Burns]

The biggest difference between standard mogas and avgas would be that avgas
is actually manufactured to a tighter Mil spec than the petroleum industry
standard for mogas. It's also handled in ways to minimize contamination.
Mogas can be transported in the same pipline or truck directly after a load
of diesel or other fuel without any cleaning procedure. Mogas and diesel
fuel can be co-mingled in the same truck, in separate compartments. Avgas
must be handled and hauled alone. Avgas can only follow mogas or after
cleaning procedures. Same for Jet A, Jet A can follow a Kerosene shipment,
but not a diesel fuel or gasoline shipment.

Jim

"Jay Honeck" > wrote in message
ups.com...
>> I noted that several of the posts mentioned small engines. Are these 4
>> strokes burning straight gas or 2 strokes burning blended gas/oil
>> mixtures?
>
> In my case, it's both. I've got an annoying mix of 2- and 4-stroke
> gasoline tools -- but none of them show any kind of problems running
> "old" gasoline.
>
> Thanks for the information about your experiences. I'm sure gasoline
> EVENTUALLY goes "bad", due to evaporation and water contamination --
> but I think it's highly unlikely that "aviation gasoline" is any
> different than "auto gasoline" in this regard.
>
> I simply don't believe that the oil companies put any extra money into
> production of aviation gasoline, especially when they sell such a
> tiny, insignificant amount of it. Does anyone (besides me) think that
> oil companies would keep the two formulas as close to identical as
> possible, with the exception of lead, in the interest of cost
> savings?
>
> Personally, I think this is just another busted aviation myth. But
> I'm sure there will always be those who believe that the $4.40/gallon
> stuff is better than the $2.89/gallon stuff, just like there are those
> who swear by Marvel Mystery Oil, flying on "the step", and fear
> stalling when turning the same direction as the wind.
>
> (Hey -- anyone want to debate "shock cooling" now that it's getting
> cold out?)
>
> :-)
> --
> Jay Honeck
> Iowa City, IA
> Pathfinder N56993
> www.AlexisParkInn.com
> "Your Aviation Destination"
>
>
>

[Matt Whiting]

Morgans wrote:

> Add me to the list. I recently got out my 6 1/2 HP Briggs overhead valve
> push mower, and it would not start when I put fresh gas in.
>
> I took the carb apart, and it is complete trash. I don't even think
> cleaning it would help. It will require a new carb.
>
> It has been about 1 1/2 years since I last used it. It is JUNK , now.
>
> Would av gas be any better? I don't know. I do believe that you had better
> keep mogas less than a year in your machines, though.

I've never had problems letting gas sit through one winter (about 5-6
months where I live), but I now use Stabil just to be on the safe side.
I had a Kawasaki KH400 that I let sit for 1.5 years once. That was a
HUGE mistake. The bike wouldn't start so I pulled the three carbs. The
float bowls were covered with a green slime that looked like algae.

I did some resarch at the time and learned that certain things actually
do live and grow in gasoline. I was finally able to clean the carbs
enough to get them working, but it took many hours of mechanical
scrubbing and poking open of fine orifices in the carbs. The green
slime was completely immune to carb cleaners, alcohol, acetone, etc. I
tried every common solvent and cleaner I had and nothing would touch
whatever that stuff was.

Matt

[Blueskies]

"Matt Whiting" > wrote in message ...
>
> I did some resarch at the time and learned that certain things actually do live and grow in gasoline. I was finally
> able to clean the carbs enough to get them working, but it took many hours of mechanical scrubbing and poking open of
> fine orifices in the carbs. The green slime was completely immune to carb cleaners, alcohol, acetone, etc. I tried
> every common solvent and cleaner I had and nothing would touch whatever that stuff was.
>
> Matt

Did you try soap and water?

[Matt Whiting]

Blueskies wrote:
> "Matt Whiting" > wrote in message ...
>> I did some resarch at the time and learned that certain things actually do live and grow in gasoline. I was finally
>> able to clean the carbs enough to get them working, but it took many hours of mechanical scrubbing and poking open of
>> fine orifices in the carbs. The green slime was completely immune to carb cleaners, alcohol, acetone, etc. I tried
>> every common solvent and cleaner I had and nothing would touch whatever that stuff was.
>>
>> Matt
>
> Did you try soap and water?
>
>

Yep. And Pine Sol. And bleach. And...

Matt

[Jim Logajan]

Matt Whiting > wrote:
> The float bowls were covered with a green slime that looked like
> algae.

Interesting. A web search suggests it could have been algae, but the web
site below (among others that have similar text) claims what you dealt with
was (probably) a formation of wax and asphalt. I can see how the latter two
would be a pain to clean out! Did you try anything like the product known
as "Goo Gone"?

http://dieselfueldoctor.com/fuel_solutions.html

[Matt Whiting]

Jim Logajan wrote:
> Matt Whiting > wrote:
>> The float bowls were covered with a green slime that looked like
>> algae.
>
> Interesting. A web search suggests it could have been algae, but the web
> site below (among others that have similar text) claims what you dealt with
> was (probably) a formation of wax and asphalt. I can see how the latter two
> would be a pain to clean out! Did you try anything like the product known
> as "Goo Gone"?
>
> http://dieselfueldoctor.com/fuel_solutions.html

No, I was not familiar with Goo Gone then (this occurred in about 1980).
Yes, I think this was more than simple algae, but I know it was the
most tenacious coating I've ever seen on aluminum!

Matt

[[email protected]]

On Sep 16, 3:09 pm, "Jim Burns" > wrote:
> The biggest difference between standard mogas and avgas would be that avgas
> is actually manufactured to a tighter Mil spec than the petroleum industry
> standard for mogas. It's also handled in ways to minimize contamination.
> Mogas can be transported in the same pipline or truck directly after a load
> of diesel or other fuel without any cleaning procedure. Mogas and diesel
> fuel can be co-mingled in the same truck, in separate compartments. Avgas
> must be handled and hauled alone. Avgas can only follow mogas or after
> cleaning procedures. Same for Jet A, Jet A can follow a Kerosene shipment,
> but not a diesel fuel or gasoline shipment.

They do the same here. The truck's tanks have to be flushed
with 100LL before they can fill them with it and the batch is tested
and a detailed printout sent with the load. The liability for Avgas is
huge compared to Mogas, and the refinery and trucking outfit have to
carry more insurance for that, too. There are many ways we pay for our
litigious society.

Dan

[M[_1_]]

On Sep 16, 2:09 pm, "Jim Burns" > wrote:
> The biggest difference between standard mogas and avgas would be that avgas
> is actually manufactured to a tighter Mil spec than the petroleum industry
> standard for mogas. It's also handled in ways to minimize contamination.
> Mogas can be transported in the same pipline or truck directly after a load
> of diesel or other fuel without any cleaning procedure. Mogas and diesel
> fuel can be co-mingled in the same truck, in separate compartments. Avgas
> must be handled and hauled alone. Avgas can only follow mogas or after
> cleaning procedures. Same for Jet A, Jet A can follow a Kerosene shipment,
> but not a diesel fuel or gasoline shipment.
>

Avgas is not transported by pipelines in the U.S. due to the existence
of TEL contaminating pipeline. They're all trucked, often from a
refinery half the country away. That's one of the big reasons why
100LL costs more than $1/gallon over mogas, and that price delta is
going to further increase as the overall consumption avgas decreases.

[M[_1_]]

As a fellow mogas flyer who burn over a thousand gallon of mogas a
year in my plane, and believing the aviation industry is stupid not
moving away from engines requiring 100LL (they should only install
gasoline engines requiring 91/96 or lower octane, or aero diesel
engines into new production planes, if you ask me), I do believe that
mogas deteriorates faster than avgas. The reason is probably due to
different chemical make-up btween mogas and avgas. Mogas's end
distillate is slightly heavier, meaning it has more larger hydrocarbon
molecules in the mix compared to avgas. It also contains a higher
percentage of aromatics hydrocarbon. Those chemical property of
mogas, when oxidized over a long period of time, tend to make the fuel
off-spec more quickly than 100LL.

http://www.generalaviationnews.com/editorial/articledetail.lasso?-token.key=13452&-token.src=column&-nothing

Look at the brighter side Jay. If we're paying $1.50/gal less in
fuel, a good chunk of our flying is free. We should simply go fly
more often.


On Sep 15, 1:45 pm, Jay Honeck > wrote:
>
> You know, I've heard that ever since I started using mogas in my
> planes, but I've never seen a cite, nor have I *ever* noticed a
> problem with unleaded gasoline in *any* of my lawn mowers, leaf
> blowers, or snow blowers.
>
> I put 'em away in the spring/winter, and start 'em up the following
> winter/summer -- and away we go. Same with my Honda Goldwing -- I
> top
> it off, and it just sits till next year. No troubles.
>
> Can anyone point me to anything that proves (or disproves) the "fact"
> that unleaded mogas deteriorates faster than avgas?
>

[Adhominem]

Jim Burns wrote:

> It's also handled in ways to minimize contamination.

I always thought the special handling was because of the lead in 100LL and
for the protection of the unleaded fuels from lead contamination, not for
the protection of the Avgas.

--
The mail address works, but please notify me via usenet of any mail you send
to it, as it has a retention period of just a few hours.

[Robert M. Gary]

On Sep 15, 8:40 pm, "Maxwell" > wrote:
> "Robert M. Gary" > wrote in glegroups.com...
>
>
>
> > It depends where you live. Out here in California they put corn or
> > whatnot in the autogas. If you leave that stuff in your mower or weed
> > eater for even 30 days you'll spend the next 30 days in the shop. I've
> > had my current weed eater in the shop 3 times this year just to clear
> > out the carb due to the crappy gas. The shops recommend always running
> > then dry and never, ever, storing gas for me than 30 days. Even at
> > that you need to have the lines cleaned to remove the sludge that the
> > mogas creates.
>
> Have you tried 100LL, or racing fuel from a local speed shop? We use so
> little in weed eaters and such, it might be worth the price.

I have but I'm concerned that the lead and high octane might create
deposits in the engine. What I need is not better gas but just clean
(even crappier) gas.

-Robert

[Robert M. Gary]

On Sep 16, 11:16 pm, M > wrote:
> As a fellow mogas flyer who burn over a thousand gallon of mogas a
> year in my plane, and believing the aviation industry is stupid not
> moving away from engines requiring 100LL (they should only install
> gasoline engines requiring 91/96 or lower octane, or aero diesel
> engines into new production planes, if you ask me), I do believe that
> mogas deteriorates faster than avgas. The reason is probably due to
> different chemical make-up btween mogas and avgas. Mogas's end
> distillate is slightly heavier, meaning it has more larger hydrocarbon
> molecules in the mix compared to avgas. It also contains a higher
> percentage of aromatics hydrocarbon. Those chemical property of
> mogas, when oxidized over a long period of time, tend to make the fuel
> off-spec more quickly than 100LL.
>
> http://www.generalaviationnews.com/editorial/articledetail.lasso?-tok...
>
> Look at the brighter side Jay. If we're paying $1.50/gal less in
> fuel, a good chunk of our flying is free. We should simply go fly
> more often.
>
> On Sep 15, 1:45 pm, Jay Honeck > wrote:
>
>
>
>
>
> > You know, I've heard that ever since I started using mogas in my
> > planes, but I've never seen a cite, nor have I *ever* noticed a
> > problem with unleaded gasoline in *any* of my lawn mowers, leaf
> > blowers, or snow blowers.
>
> > I put 'em away in the spring/winter, and start 'em up the following
> > winter/summer -- and away we go. Same with my Honda Goldwing -- I
> > top
> > it off, and it just sits till next year. No troubles.
>
> > Can anyone point me to anything that proves (or disproves) the "fact"
> > that unleaded mogas deteriorates faster than avgas?- Hide quoted text -

But is there any real future in mogas for aircraft. Its getting pretty
hard to find FAA legal mogas. Out here in California almost all mogas
is prohibited by the STC's.

-Robert

[Gig 601XL Builder]

Robert M. Gary wrote:
>
> But is there any real future in mogas for aircraft. Its getting pretty
> hard to find FAA legal mogas. Out here in California almost all mogas
> is prohibited by the STC's.
>
> -Robert

I spent some time with a friend that is fairly high up the corporate latter
of one of the top 15 oil companies this weekend and we were discussing just
this. He said in the states that do not require marking of gas with or
without ethanol, Arkansas being one of them. That the chance of you buying
gas without ethanol over the long run is pretty much zero. Even in those
states that do have marking requirements the chances of getting a batch that
has it even in an unmarked pump are going to be pretty good.

[RST Engineering]

The hell of it is, Robert, that the mogas is perfectly legal until they dump
it in the delivery trailer along with the prescribed amount of ethanol. The
refinery will sell you all the legal mogas you want so long as you can take
8000 gallon loads.

Jim

--
"If you think you can, or think you can't, you're right."
--Henry Ford



> hard to find FAA legal mogas. Out here in California almost all mogas
> is prohibited by the STC's.
>
> -Robert
>

[Dana M. Hague]

On Mon, 17 Sep 2007 06:16:42 -0000, M > wrote:

>
>...I do believe that
>mogas deteriorates faster than avgas. The reason is probably due to
>different chemical make-up btween mogas and avgas. Mogas's end
>distillate is slightly heavier, meaning it has more larger hydrocarbon
>molecules in the mix compared to avgas...

My understanding is that the vapor pressure of avgas is lower than
mogas, to prevent vapor lock at high altitudes. This would make it
keep longer if the storage container isn't perfectly sealed, as mogas
would lose more of the volatile fractions. It would also explain why
avgas plain smells better.

For 2-stroke flyers, there are also concerns about the longevity of
premixed fuel/oil (another endless topic on the ultralight boards).

-Dana
--
--
If replying by email, please make the obvious changes.
-------------------------------------------------------------------------------
They say that politics makes strange bedfellows.
Of course, the main reason they cuddle up is to screw somebody else.

[Cubdriver]

On Mon, 17 Sep 2007 10:53:08 -0700, "Robert M. Gary"
> wrote:

>> Have you tried 100LL, or racing fuel from a local speed shop? We use so
>> little in weed eaters and such, it might be worth the price.
>
>I have but I'm concerned that the lead and high octane might create
>deposits in the engine. What I need is not better gas but just clean
>(even crappier) gas.

The local airport (7B3 Hampton NH) sells mogas bought from the
terminal in Portland ME that has no additivates whatever. I buy it
($3.90 a gallon) for the small engines (chain saw, generator,
off-season lawnmower and snow blower) that are likely to sit for
months between uses.

Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com

[Blueskies]

"Matt Whiting" > wrote in message ...
> Jim Logajan wrote:
>> Matt Whiting > wrote:
>>> The float bowls were covered with a green slime that looked like
>>> algae.
>>
>> Interesting. A web search suggests it could have been algae, but the web site below (among others that have similar
>> text) claims what you dealt with was (probably) a formation of wax and asphalt. I can see how the latter two would be
>> a pain to clean out! Did you try anything like the product known as "Goo Gone"?
>>
>> http://dieselfueldoctor.com/fuel_solutions.html
>
> No, I was not familiar with Goo Gone then (this occurred in about 1980). Yes, I think this was more than simple algae,
> but I know it was the most tenacious coating I've ever seen on aluminum!
>
> Matt

Maybe "simple green" would take it off.... ;-)

[M[_1_]]

On Sep 17, 3:54 pm, Dana M. Hague
<d(dash)m(dash)hague(at)comcast(dot)net> wrote:

> My understanding is that the vapor pressure of avgas is lower than
> mogas, to prevent vapor lock at high altitudes. This would make it
> keep longer if the storage container isn't perfectly sealed, as mogas
> would lose more of the volatile fractions. It would also explain why
> avgas plain smells better.
>

Vapor pressure of avgas is lower than winter mogas, but it's more or
less the same as the summer mogas these days, thanks to EPA and state
air regulations bringing down vapor pressure of mogas. There are
areas in the country where summer mogas vapor pressure is required to
be 6.5, even lower than avgas.

I believe the stronger smell of mogas came mostly from its much higher
aromatic content compared to avags. Tuluene has a very strong smell.

[RST Engineering]

Tuluene has a very strong smell.
>

I'll bet if you were a graduate of Tuluene you wouldn't say that.

{;-)

Jim

[Cubdriver]

On Mon, 17 Sep 2007 18:54:09 -0400, Dana M. Hague
<d(dash)m(dash)hague(at)comcast(dot)net> wrote:

> It would also explain why
>avgas plain smells better.

It certainly does smell better!

The Cubs at Hampton Airfield were STC'd for mogas but now run entirely
on 100LL. A couple of reasons, one of which being that the instructors
complained too bitterly about the smell in the front seat.


Blue skies! -- Dan Ford

Claire Chennault and His American Volunteers, 1941-1942
new from HarperCollins www.FlyingTigersBook.com