"Over time, Mogas deteriorates faster than Avgas"

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...er =ADA174091

Chevron says mogas is good for at least a year:

http://www.chevron.com/products/prod...term_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/prod...8_ag_perf.shtm

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


Ron Wanttaja

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/prod...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

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"

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/gasol.../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

"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

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

"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?

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

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

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