Getting auto gas at airports

[Patrick Underwood]

There seem to be a lot of people using auto engines on their
homebuilts. I am a low-time student pilot so pardon me if this is a
stupid question, but do many airports have autogas available at their
pumps?

If you're doing cross-country flights, seems like it would be a huge
problem if your refueling stops didn't have the kind of fuel you need.

If airports don't have autogas, what do you do in this situation?

Thanks,
Patrick

[[email protected]]

Patrick Underwood > wrote:
: There seem to be a lot of people using auto engines on their
: homebuilts. I am a low-time student pilot so pardon me if this is a
: stupid question, but do many airports have autogas available at their
: pumps?

: If you're doing cross-country flights, seems like it would be a huge
: problem if your refueling stops didn't have the kind of fuel you need.

: If airports don't have autogas, what do you do in this situation?

You can (almost) always run a gas that has a higher octane than
what your engine requires, so if you normally run 87 cargas (something
like 82 avgas rating), then flying somewhere that only has 100LL, you can
burn that without trouble. Aside from the lead fouling and the price,
100LL is a much "better" (cleaner, tigher tolerances, lower vapor
pressure, etc) fuel than cargas, but if your engine can run on cargas, it
can be a good cost saver.

Some airports do have autogas, and it tends to have a slight cost
savings over avgas. Check fuel info at http://www.airnav.com

Cheers
-Cory

--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************

[Jerry Wass]

avgas!

Patrick Underwood wrote:

> There seem to be a lot of people using auto engines on their
> homebuilts. I am a low-time student pilot so pardon me if this is a
> stupid question, but do many airports have autogas available at their
> pumps?
>
> If you're doing cross-country flights, seems like it would be a huge
> problem if your refueling stops didn't have the kind of fuel you need.
>
> If airports don't have autogas, what do you do in this situation?
>
> Thanks,
> Patrick

[David Hill]

wrote:
<snip>
> Some airports do have autogas, and it tends to have a slight cost
> savings over avgas. Check fuel info at http://www.airnav.com
<snip>

I'd still call ahead and find out if they have mogas. For instance, the
listing for my local airport, AJR, shows that it has mogas, but they
don't; something about the fuel supplier saying he would cut them off if
they didn't quit selling mogas.

--
David Hill
david at hillREMOVETHISfamily.org
Sautee-Nacoochee, GA, USA

[Ron Natalie]

> wrote in message ...

> You can (almost) always run a gas that has a higher octane than
> what your engine requires, so if you normally run 87 cargas (something
> like 82 avgas rating), then flying somewhere that only has 100LL, you can
> burn that without trouble.

Well the octane numbers aren't directly comparable. The major reason you
can run 100LL is because your aircraft was originally certificated for 80 or
100 octane Avgas. The STC doesn't undo the original certification, just adds
the option of of using autogas.

[Russell Kent]

Ron Natalie wrote:

> Well the octane numbers aren't directly comparable. The major reason you
> can run 100LL is because your aircraft was originally certificated for 80 or
> 100 octane Avgas. The STC doesn't undo the original certification, just adds
> the option of of using autogas.

While what Ron writes (above) is true, it isn't directly on point because of thread drift. The
originator specifically said "auto engines in homebuilts". * Unless the homebuilder (or
firewall-forward packager) has done womething *really* strange, the only problem with using
Aviation 100LL in an auto engine is the lead in 100LL: it *may* foul the plugs, poison the O2
sensor (if engine has one), and sludge the oil (depending on the oil type).

Russell Kent

(*) Shaddup BOb. :-)

[Bob Fry]

David Hill > writes:

> I'd still call ahead and find out if they have mogas. For instance,
> the listing for my local airport, AJR, shows that it has mogas, but
> they don't; something about the fuel supplier saying he would cut them
> off if they didn't quit selling mogas.

Have you entered a correction?

[[email protected]]

Ron Natalie > wrote:
:> You can (almost) always run a gas that has a higher octane than
:> what your engine requires, so if you normally run 87 cargas (something
:> like 82 avgas rating), then flying somewhere that only has 100LL, you can
:> burn that without trouble.

: Well the octane numbers aren't directly comparable. The major reason you
: can run 100LL is because your aircraft was originally certificated for 80 or
: 100 octane Avgas. The STC doesn't undo the original certification, just adds
: the option of of using autogas.

That's true, they're not directly comparable. The sticker at the
pump is an "Anti-Knock Index" or A.K.I, which is the average of the octane
measured using the Motor method, and the Research method. For typical
autogas, the difference between the two is about 10 points, so for 87 AKI,
the Motor rating is about 82, and the Research rating is about 92. The
Motor rating is very similar to the avgas lean rating. Thus the comment
that 87 AKI cargas is roughly equivalent to 82 avgas. Also not a
coincidence that the new unleaded avgas is called 82UL... basically cargas
with traceable handling and ensured free of arbitrary additives. The
avgas rich rating comparison is anyone's guess.

-Cory



--
************************************************** ***********************
* The prime directive of Linux: *
* - learn what you don't know, *
* - teach what you do. *
* (Just my 20 USm$) *
************************************************** ***********************