Fuel prices--BTU's per gal.

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in
a GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

"Jerry Wass" wrote in message
. net...
Hate to disagree. but there are more BYU's in a GALLON of Avgas than in a
GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

More BYUs? Let see...BYU, BYU Hawaii, and BYU Idaho. How do you get all of
those universities in a gallon of avgas?

"Jerry Wass" wrote in message
. net...
Hate to disagree. but there are more BYU's in a GALLON of Avgas than in a
GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

More BYUs? Let see...BYU, BYU Hawaii, and BYU Idaho. How do you get all of
those universities in a gallon of avgas?

"Jerry Wass" wrote

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in a
GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

I may have to back up off of that statement, and I'll tell you my (possible)
faulty reasoning.

Generally, the more refined, higher octane fuel will have less BTU content.

I "forgot" to take into account that the primary way that 100LL gets its
high octane rating is by the use of lead. That throws things off a little
bit.
--
Jim in NC

"Morgans" wrote in message
...

"Jerry Wass" wrote

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in
a
GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

I may have to back up off of that statement, and I'll tell you my
(possible)
faulty reasoning.

Generally, the more refined, higher octane fuel will have less BTU
content.

I "forgot" to take into account that the primary way that 100LL gets its
high octane rating is by the use of lead. That throws things off a little
bit.
--
Jim in NC


Very true, although I don't know enough chemistry to understand just why the
fuels with the higher octane number are generally less dense. Fortunately,
the lead is probably a small fraction of one percent of the fuel by weight.
However, in the case of Mogas, the addition of unknown quantities of so
called oxigenates, such as ethanol, the energy content per unit is reduced
by some amount.

When measuring fuel by volume (usually gallons or litres) the ethanol is
said to contain approximately 60% of the energy of gasolene--that is simply
the relationship which I have heard/read consistently repeated. Thus, Mogas
that contains 10% ethanol should contain about 96% as much energy as "real"
gasolene.

When measuring by weight, I suspect that the result is slightly worse. My
recollection from physics class is that an oxigen atom is about the same
size as a carbon atom and slightly heavier; so that the ethanol should be
slightly heavier by volume. However, the oxigen atom contributes nothing to
energy content--since ample oxigen is readily available from the air.
Therefore, with the caveat that my knowledge of molecular structure and
density is not strong; the effect of ethanol on energy content by weight is
probably worse than by volume. As a guess, Mogas that is 10% ethanol by
volume probably contains about 95% as much energy, per pound or per
kilogram, compared to "real" gasolene--despite being more hygroscopic and
(so they say) also slightly more expensive to produce.

Peter

Jerry Wass wrote:

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in
a GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

From Wikipedia, the free encyclopedia:

Energy content

Gasoline contains about 34.6 megajoules per litre (MJ/l) or 131 MJ/US
gallon. This is an average, gasoline blends differ, therefore actual
energy content varies from season to season and from batch to batch,
as much as 4% more or less than the average, according to the US EPA.


Fuel type BTU/US gal Research octane

Regular Gasoline 125,000 Min 91

Aviation gasoline 120,200


- Barnyard BOb -

On Mon, 28 May 2007 00:27:21 GMT, Jerry Wass
wrote:

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in
a GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

From Wikipedia, the free encyclopedia:

Energy content

Gasoline contains about 34.6 megajoules per litre (MJ/l) or 131 MJ/US
gallon. This is an average, gasoline blends differ, therefore actual
energy content varies from season to season and from batch to batch,
as much as 4% more or less than the average, according to the US EPA.


Fuel type BTU/US gal Research octane

Regular Gasoline 125,000 Min 91
Aviation gasoline 120,200


BTU/US gal
Gasohol (10% ethanol + 90% gasoline) 120,900
( Research octane) 93/94


- Barnyard BOb -

"Barnyard BOb" wrote

From Wikipedia, the free encyclopedia:

Fuel type BTU/US gal Research octane

Regular Gasoline 125,000 Min 91

Aviation gasoline 120,200

Why, Barnyard BoB, I would like to thank you for that information.

I really didn't think you cared, but you must, since you backed up my
original claim! g
--
Jim in NC

"Barnyard BOb" wrote in message
...
On Mon, 28 May 2007 00:27:21 GMT, Jerry Wass
wrote:

Hate to disagree. but there are more BYU's in a GALLON of Avgas than in
a GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-

From Wikipedia, the free encyclopedia:

Energy content

Gasoline contains about 34.6 megajoules per litre (MJ/l) or 131 MJ/US
gallon. This is an average, gasoline blends differ, therefore actual
energy content varies from season to season and from batch to batch,
as much as 4% more or less than the average, according to the US EPA.


Fuel type BTU/US gal Research octane

Regular Gasoline 125,000 Min 91
Aviation gasoline 120,200


BTU/US gal
Gasohol (10% ethanol + 90% gasoline) 120,900
( Research octane) 93/94


- Barnyard BOb -

Most interesting.

Thanks for the update.

Peter

Wayne Paul wrote:
"Jerry Wass" wrote in message
. net...
Hate to disagree. but there are more BYU's in a GALLON of Avgas than in a
GALLON of Mogas. Why?? Avgas weighs more per Gallon...

Most fuel type hydrocarbons have nearly the same BTU's per Lb.

More BYUs? Let see...BYU, BYU Hawaii, and BYU Idaho. How do you get all of
those universities in a gallon of avgas?



BTU is British Thermal Unit...So there's no bacon at all in it?