Question on fuel consumption

[Shemp McGurk]

The government routinely publishes a list of miles-per-gallon
consumption ratings for all cars sold in the U.S.

Does anyone know whether such a list exists for aviation?

I'm looking for a list of fuel consumption ratings for:

- private jets

- commercial jets.

....AND, if such a list exists, a per-passenger fuel consumption by
type of aircraft.

I thank you in advance for your answers...

[Cub Driver]

Zero Six Hotel burns four gallons an hour on average, if that helps :)

all the best -- Dan Ford
email: (put Cubdriver in subject line)

Warbird's Forum www.warbirdforum.com
Piper Cub Forum www.pipercubforum.com
the blog www.danford.net

[Peter R.]

Cub Driver ) wrote:

> Zero Six Hotel burns four gallons an hour on average, if that helps :)

.... during it's fifty nm journey in a no wind situation. ;-)

--
Peter

[Nathan Young]

On 20 Oct 2004 23:39:55 -0700, (Shemp McGurk)
wrote:

>The government routinely publishes a list of miles-per-gallon
>consumption ratings for all cars sold in the U.S.
>
>Does anyone know whether such a list exists for aviation?
>
>I'm looking for a list of fuel consumption ratings for:
>
>- private jets
>
>- commercial jets.
>
>...AND, if such a list exists, a per-passenger fuel consumption by
>type of aircraft.
>
>I thank you in advance for your answers...


Most small aircraft are on par with SUVs from a miles per gallon
standpoint.

For example, my Cherokee 180 consumes 10gph while cruising at 145mph
for 14.5mpg. The plane is flying directly to the destination (versus
following a curved road), so 14.5mpg in a plane is approximately
15-20% better than 14.5mpg in a car.

-Nathan

[C Kingsbury]

"Shemp McGurk" > wrote in message
om...
>
> Does anyone know whether such a list exists for aviation?

Nope. Too many variables. Winds, air temperature, and payload all affect
this pretty significantly, particularly in jets. Not to mention the huge
variety of airframe/engine combos out there.

> I'm looking for a list of fuel consumption ratings for:
>
> - private jets
>
> - commercial jets.
>
> ...AND, if such a list exists, a per-passenger fuel consumption by
> type of aircraft.
>
> I thank you in advance for your answers...

If you don't need a precise number, look at the aircraft's range with
maximum fuel and its fuel capacity. You can get this from the manufacturers'
websites. Jets typically think about fuel consumption in pounds, so keep in
mind there are about 6 pounds of Jet-A to the gallon.

Regarding weight, there are a few numbers you can look at: MGTOW (max gross
takeoff weight), empty weight, and "payload with full fuel." If they don't
list how much fuel it carries for maximum range, look at the weights.
Generally speaking, fuel weight will equal MGTOW minus empty weight minus
full fuel payload.

FYI, I once ballparked a Gulfstream V's fuel consumption as something like 1
gallon per mile, and a 747-400's as 6 gallons per mile.

If there's a specific scenario you're trying to examine (i.e. Learjet versus
Hummer H2) I suggest asking that question specifically. Odds are someone
here will be able to provide far more precise numbers than I could.

Also, you might try calling a local jet charter operator. They can surely
give you numbers for the planes they operate.

Best,
-cwk.

[Malcolm Teas]

(Shemp McGurk) wrote in message >...
> The government routinely publishes a list of miles-per-gallon
> consumption ratings for all cars sold in the U.S.
>
> Does anyone know whether such a list exists for aviation?

Miles per gallon measurements don't work that well for airplanes.
After all, there's factors like the plane's headwind or tailwind
speed, and that airplane engines run at higher power output ratings in
cruise than do cars. Flying with a headwind is like driving west at
70 MPH on a road that's moving east at 30 MPH. You're only doing 40
MPH relative to the trees on the side of the road. With a tailwind
it's opposite. And, most of the time you're dealing with one or the
other.

A car is rarely run over 40%-50% of potential power output. While
higher power's useful for hills, or for passing, the average RPM is
much much lower than the max. Airplanes, though, typically run
60%-80% of full power in the cruise phase of flight, the longest phase
by far. So, you're comparing apples and oranges here.

For these and other reasons, airplanes are usually figured at
gallons/hour consumption.

-Malcolm Teas

[Morgans]

"Malcolm Teas" > wrote
>
> Miles per gallon measurements don't work that well for airplanes.
> After all, there's factors like the plane's headwind or tailwind
> speed,

airplanes are usually figured at
> gallons/hour consumption.
>
> -Malcolm Teas

Yes, we all know that, but approximations (meaningful ones) can still be
made. Yes, you would have to figure with no headwind, and direct route, (or
airways for big stuff) and you would do the same for the ground
transportation. Reality would be different, but that is beside the point.

Figure fuel used for a round trip to a destination far enough away to allow
getting to cruise altitude, then figure gas mileage for a car for the same
destination, and there you have it.
--
Jim in NC


---
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[C J Campbell]

"Shemp McGurk" > wrote in message
om...
> The government routinely publishes a list of miles-per-gallon
> consumption ratings for all cars sold in the U.S.
>
> Does anyone know whether such a list exists for aviation?
>

It does not exist. The usual method of predicting fuel mileage in an
airplane is to take the gallons per hour, which is relatively constant at a
particular altitude and power setting, and then find out how long it will
take to reach the destination, taking into account wind, payload, and other
factors.

Some small single piston engine planes can easily exceed thirty miles per
gallon, while others are doing well to get a third of that.

Most of the manufacturers post performance specs on their web sites for
various models of aircraft. Boeing, Airbus, Raytheon (Beech), Bombardier,
Cessna, Cirrus, Piper, Lancair, Mooney, Diamond and many other manufacturers
all maintain good web sites that will tell you how their airplanes perform.

Most pilots would look at a government listing of miles per gallon with some
suspicion anyway. Pilots like their fuel consumption figures to be a little
more accurate than the list that is published for automobiles. After all, we
can't just pull over to the side of the road if we run out of gas.

[Icebound]

"C Kingsbury" > wrote in message
ink.net...
>
> If you don't need a precise number, look at the aircraft's range with
> maximum fuel and its fuel capacity. You can get this from the
> manufacturers'
> websites. Jets typically think about fuel consumption in pounds, so keep
> in
> mind there are about 6 pounds of Jet-A to the gallon.
>

Avgas is 6 pounds, but I think Jet Fuel is 6.5

http://www.fs.fed.us/im/directives/fsh/5709.16/5709.16_30.txt

[Shemp McGurk]

"C Kingsbury" > wrote in message et>...
> "Shemp McGurk" > wrote in message
> om...
> >
> > Does anyone know whether such a list exists for aviation?
>
> Nope. Too many variables. Winds, air temperature, and payload all affect
> this pretty significantly, particularly in jets. Not to mention the huge
> variety of airframe/engine combos out there.
>
> > I'm looking for a list of fuel consumption ratings for:
> >
> > - private jets
> >
> > - commercial jets.
> >
> > ...AND, if such a list exists, a per-passenger fuel consumption by
> > type of aircraft.
> >
> > I thank you in advance for your answers...
>
> If you don't need a precise number, look at the aircraft's range with
> maximum fuel and its fuel capacity. You can get this from the manufacturers'
> websites. Jets typically think about fuel consumption in pounds, so keep in
> mind there are about 6 pounds of Jet-A to the gallon.
>
> Regarding weight, there are a few numbers you can look at: MGTOW (max gross
> takeoff weight), empty weight, and "payload with full fuel." If they don't
> list how much fuel it carries for maximum range, look at the weights.
> Generally speaking, fuel weight will equal MGTOW minus empty weight minus
> full fuel payload.
>
> FYI, I once ballparked a Gulfstream V's fuel consumption as something like 1
> gallon per mile, and a 747-400's as 6 gallons per mile.
>
> If there's a specific scenario you're trying to examine (i.e. Learjet versus
> Hummer H2) I suggest asking that question specifically. Odds are someone
> here will be able to provide far more precise numbers than I could.



Actually, your Gulfstream V comparison with the 747-400 is exactly the
kind of thing I'm looking for: the per-passenger miles-per-gallon on a
private jet versus the per-passenger miles-per-gallon on a commercial
jet.

And from the example you give above, it's about what I thought it
would be: a 747 with, say, 300 passengers is consuming 6 gallons per
mile and a Gulfstream with, say, 10 passengers is consuming 1 gallon
per mile, the per-passenger miles-per-gallon is WAY higher with the
private jet than with the commercial jet.

Yes?


>
> Also, you might try calling a local jet charter operator. They can surely
> give you numbers for the planes they operate.
>
> Best,
> -cwk.

[Peter Duniho]

"Shemp McGurk" > wrote in message
m...
> [...]
> And from the example you give above, it's about what I thought it
> would be: a 747 with, say, 300 passengers is consuming 6 gallons per
> mile and a Gulfstream with, say, 10 passengers is consuming 1 gallon
> per mile, the per-passenger miles-per-gallon is WAY higher with the
> private jet than with the commercial jet.

You have that backwards (maybe because the mileages were stated reverse from
what we're used to in the US).

300 passengers in an airplane that's getting 1/6th of a mile per gallon
winds up being 50 passenger-miles per gallon, while 10 passengers in an
airplane that's getting 1 mile per gallon winds up being 10 passenger-miles
per gallon. The 747 has better mileage by a factor of 5.

That's assuming the figures are actually correct, of course. I can't speak
on whether they are or not.

Pete

[Cub Driver]

>> Zero Six Hotel burns four gallons an hour on average, if that helps :)
>
>... during it's fifty nm journey in a no wind situation. ;-)

Actually, the fuel burn is the same whether the wind is blowing or
not.

It's true that with a 20-knot wind the outbound journey will take a
bit longer than the return. (20-knot winds hereabouts almost always
come from the NNW, which is where I am generally going.)

all the best -- Dan Ford
email: (put Cubdriver in subject line)

Warbird's Forum www.warbirdforum.com
Piper Cub Forum www.pipercubforum.com
the blog www.danford.net

[Peter R.]

Cub Driver ) wrote:

> >> Zero Six Hotel burns four gallons an hour on average, if that helps :)
> >
> >... during it's fifty nm journey in a no wind situation. ;-)
>
> Actually, the fuel burn is the same whether the wind is blowing or
> not.

I was trying to make a joke about the Cub's no wind ground speed.


--
Peter

[Peter R.]

Peter R. ) wrote:

> Cub Driver ) wrote:
>
> > >> Zero Six Hotel burns four gallons an hour on average, if that helps :)
> > >
> > >... during it's fifty nm journey in a no wind situation. ;-)
> >
> > Actually, the fuel burn is the same whether the wind is blowing or
> > not.
>
> I was trying to make a joke about the Cub's no wind ground speed.

Whoops, I left off this :)


--
Peter

[Shemp McGurk]

"Peter Duniho" > wrote in message >...
> "Shemp McGurk" > wrote in message
> m...
> > [...]
> > And from the example you give above, it's about what I thought it
> > would be: a 747 with, say, 300 passengers is consuming 6 gallons per
> > mile and a Gulfstream with, say, 10 passengers is consuming 1 gallon
> > per mile, the per-passenger miles-per-gallon is WAY higher with the
> > private jet than with the commercial jet.
>
> You have that backwards (maybe because the mileages were stated reverse from
> what we're used to in the US).


Yes, you're right...I have it backwards but I meant to say what YOU
say below. Instad of saying "WAY higher" I meant to say "WAY worse".

>
> 300 passengers in an airplane that's getting 1/6th of a mile per gallon
> winds up being 50 passenger-miles per gallon, while 10 passengers in an
> airplane that's getting 1 mile per gallon winds up being 10 passenger-miles
> per gallon. The 747 has better mileage by a factor of 5.
>
> That's assuming the figures are actually correct, of course. I can't speak
> on whether they are or not.
>
> Pete

[Mike Rapoport]

Of course this is basically true for any two aircraft, the larger one will
get more passenger miles per gallon. A 777 gets a lot more than a 737 for
instance. The same is true for car vs bus.

Mike
MU-2

"Shemp McGurk" > wrote in message
om...
> "Peter Duniho" > wrote in message
> >...
>> "Shemp McGurk" > wrote in message
>> m...
>> > [...]
>> > And from the example you give above, it's about what I thought it
>> > would be: a 747 with, say, 300 passengers is consuming 6 gallons per
>> > mile and a Gulfstream with, say, 10 passengers is consuming 1 gallon
>> > per mile, the per-passenger miles-per-gallon is WAY higher with the
>> > private jet than with the commercial jet.
>>
>> You have that backwards (maybe because the mileages were stated reverse
>> from
>> what we're used to in the US).
>
>
> Yes, you're right...I have it backwards but I meant to say what YOU
> say below. Instad of saying "WAY higher" I meant to say "WAY worse".
>
>>
>> 300 passengers in an airplane that's getting 1/6th of a mile per gallon
>> winds up being 50 passenger-miles per gallon, while 10 passengers in an
>> airplane that's getting 1 mile per gallon winds up being 10
>> passenger-miles
>> per gallon. The 747 has better mileage by a factor of 5.
>>
>> That's assuming the figures are actually correct, of course. I can't
>> speak
>> on whether they are or not.
>>
>> Pete

[Chris W]

Shemp McGurk wrote:

>Actually, your Gulfstream V comparison with the 747-400 is exactly the
>kind of thing I'm looking for: the per-passenger miles-per-gallon on a
>private jet versus the per-passenger miles-per-gallon on a commercial
>jet.
>
>And from the example you give above, it's about what I thought it
>would be: a 747 with, say, 300 passengers is consuming 6 gallons per
>mile and a Gulfstream with, say, 10 passengers is consuming 1 gallon
>per mile, the per-passenger miles-per-gallon is WAY higher with the
>private jet than with the commercial jet.
>
>Yes?
>
>
The basic concept is the same for airplanes as it is for ground
vehicles. The larger the vehicle the better the "payload mile per
gallon". If you consider the payload of a new 18 wheeler that gets, I
think, over 6 miles/per gallon, to that of the say 40 mpg of some small
cars, you will find that per pound of payload the 18 wheeler gets a lot
better millage. The same is true for airplanes. I would also bet, with
out knowing the exact numbers, that a 777 has a higher "payload mile per
gallon" than a 40 mpg Honda civic. If you go by Payload mile per gallon
per hour of transit time, the 777 number would eclipse the Honda number.

--
Chris W

Not getting the gifts you want? The Wish Zone can help.
http://thewishzone.com

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

[John Galban]

"C J Campbell" > wrote in message >...
<snip>
> Some small single piston engine planes can easily exceed thirty miles per
> gallon, while others are doing well to get a third of that.
>

I'm curious, CJ. Can you provide an example of a light single that
easily exceeds 30 mpg? Most of the more common ones (172, PA28,
etc..) tend to average around 15 to 18 mpg, depending on the power
setting.

John Galban=====>N4BQ (PA28-180)

[Pat D. Halpin]

Shemp McGurk wrote:
<snip>
> I'm looking for a list of fuel consumption ratings for:
>
> - private jets
>
> - commercial jets.
>
> ...AND, if such a list exists, a per-passenger fuel consumption by
> type of aircraft.

This spreadsheet-

http://www.arising.com.au/aviation/AircraftComparison.htm

isn't a perfect match but it may be of interest to the OP and others.

[Nathan Young]

On 22 Oct 2004 13:58:31 -0700, (John Galban)
wrote:

>"C J Campbell" > wrote in message >...
><snip>
>> Some small single piston engine planes can easily exceed thirty miles per
>> gallon, while others are doing well to get a third of that.
>>
>
> I'm curious, CJ. Can you provide an example of a light single that
>easily exceeds 30 mpg? Most of the more common ones (172, PA28,
>etc..) tend to average around 15 to 18 mpg, depending on the power
>setting.

30 mpg is tough to come by in a plane, but some of the smaller
experimentals can probably do it.

The Q200 and Pulsar come to mind. Both are running 180mph
around 6gph.

[C Kingsbury]

"Mike Rapoport" > wrote in message
ink.net...
> Of course this is basically true for any two aircraft, the larger one will
> get more passenger miles per gallon. A 777 gets a lot more than a 737 for
> instance. The same is true for car vs bus.

There are two numbers that tell the story: the weight of the vehicle per
passenger carried, and the speed at which the vehicle travels. All other
things being equal, it takes more power (and thus fuel) to carry more
weight, and more power to carry a given amount of weight faster. If I
throttled my 172 back to highway speeds I suspect the fuel consumption would
rival many cars', though the same could not be said for payload.

One interesting result of this is that many more modern passenger jets
consume less fuel per passenger-mile than high-speed trains, because the
trains carry a lot more dead weight per passenger. It is thus quite likely
that the BOS-LGA shuttle operates at a higher fuel efficiency than the
high-speed Amtrak train making the same trip.

Best,
-cwk.

[C J Campbell]

"John Galban" > wrote in message
om...
> "C J Campbell" > wrote in message
>...
> <snip>
> > Some small single piston engine planes can easily exceed thirty miles
per
> > gallon, while others are doing well to get a third of that.
> >
>
> I'm curious, CJ. Can you provide an example of a light single that
> easily exceeds 30 mpg? Most of the more common ones (172, PA28,
> etc..) tend to average around 15 to 18 mpg, depending on the power
> setting.

I know a guy who claims to get that in his Long-EZ, and my brother says he
will probably get that or better in his Celerity Mirage if he ever finishes
it.

[Chris W]

John Galban wrote:

> I'm curious, CJ. Can you provide an example of a light single that
>easily exceeds 30 mpg? Most of the more common ones (172, PA28,
>etc..) tend to average around 15 to 18 mpg, depending on the power
>setting.
>
>
The Van's Aircraft RVs get right around 25 mpg

--
Chris W

Not getting the gifts you want? The Wish Zone can help.
http://thewishzone.com

"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

[Paul Sengupta]

"Mike Rapoport" > wrote in message
ink.net...
> Of course this is basically true for any two aircraft, the larger one will
> get more passenger miles per gallon. A 777 gets a lot more than a 737 for
> instance. The same is true for car vs bus.

Not always the case. From the SAS website, the efficiencies of their various
aircraft:

Family: DH-Q400 (turboprop)
Q400, 58-72 seats, 0.039 liters per seat / km

Family: MD-80 series
MD87, 110-125 seats, 0.048 liters per seat / km (JT8D)
MD81/82, 141-145 seats, 0.043 liters per seat / km (JT8D)
MD90, 147 seats, 0.039 liters per seat / km (V2500)

Family: 737 (all CFM-56)
737-600, 123 seats, 0.044 liters/seat km
737-700, 131 seats, 0.042liters/seat km
737-800, 179 seats, 0.034 liters/seat km

Family: A320
A321-200, 184 seats, 0.031 liters / seat km (V2500)

Family: A330/A340
A330-300, 261 seats, 0.035 liter / seat km (Trent 700)
A340-300, 261 seats, 0.039 liters / seat km (CFM-56)

The bigger planes or those with more efficient engines in each family
do better but it's not necessarily the case that the bigger planes are
more efficient. However you can't compare these exactly as the
short haul are probably more densely packed with seats than long
haul.

Paul

[David CL Francis]

On Fri, 22 Oct 2004 at 23:50:36 in message
et>, C Kingsbury
> wrote:
>One interesting result of this is that many more modern passenger jets
>consume less fuel per passenger-mile than high-speed trains, because the
>trains carry a lot more dead weight per passenger. It is thus quite likely
>that the BOS-LGA shuttle operates at a higher fuel efficiency than the
>high-speed Amtrak train making the same trip.

What matters is drag. On the level a train may be heavy but its friction
is very low.

Rolling friction is roughly 10lb per ton or a bit less. So a train on
level ground has a 'Lift' to drag ratio of 224. Air drag is a tiny part
of a train's drag but let's say assume it easily achieves 200 to 1. For
a 747-400 let's assume that it has a lift drag of 20 to 1. In cruise at
say 705,000 lb. the 747 drag is therefore around 35,250 lb.. A train
with about the same drag could therefore weigh around 3,250 tons. They
both need a lot of energy to climb and the weight of train may be
against it but they don't have to climb above 30,000 ft! :-)

Let me know the AUW weight of the high speed Amtrak train and I can do
it bit better.

Incidentally the drag of an aircraft flying at its maximum Lift/Drag
ratio is the same at all heights. But at altitude it flies much faster
for the same drag.

So some questions for you. Do modern jet airliners use less fuel per
mile by flying higher or do they just get there quicker? Or perhaps the
engine efficiency is much higher at altitude? Better specific thrust
perhaps?
--
David CL Francis