Accord 04 mileage improved if in-coming air is heated?

>For what it's worth, I drive in those temperatures a lot in the
>winter, as well as 100+ in the summer. I don't notice what you are
>seeing. 1999 and 2003 Accord V-6's, as well as a 1993 Jeep Grand
>Cherokee.

>Dick

I saw that in my 99 and 04 accord both 4 cyl
I could hardly see that in my 94 intrepid 6 cyl.
Likely it is a honda design . You are right. Honda engineer would have
dealt with that if simple preheating intake air would cure it.
I am located in toronto really not an extremely cold area at all.

Daniel

wrote:
>
> My accord 04 4 cyl mileage drops by 10-15% in winter time and I have
> measured that miticulously.
>
> If I can somehow warm up likely through passive means not by 12V) the
> incoming air before the airfilter, will that improve mileage?
>
> I am talking about temp around 30 F or 0 C only and it is very obvious.
>
> My 99 accord did the same thing. Any input from this NG is
> appreciated.
>
> Daniel

------------------------------


Start the car, brush off the snow, get in and drive like a 'little old
lady' for the first two minutes. Don't install a remote starter. Like
someone else pointed out, winter gas is also poor for mileage. :-(

'Curly'

On Sat, 19 Nov 2005 17:38:47 -0800, jim beam >
wrote:

>> Another factor, often overlooked, is that the denser air increases
>> wind resistance.
>
>true.
>
>> This is a very significant factor on the highway.
>> (Any pilot will tell you about the huge increase in performance of an
>> aircraft going from 70F to 0F.
>
>doesn't this contradict your air density statement?

No. Unlike cars, airplanes use air for lift. Greater air density =
greater performance. The engine also develops more horsepower with
denser air.

>
>> They will also tell you about the
>> increased economy of flying at higher altitude where air density - and
>> aircraft performance - is reduced.) Obviously, heating the intake air
>> will do nothing to help you there.
>
>dude, you're all over the shop. density increases as temperature drops.
>density decreases as you increase altitude.

Right.

> that's not the same thing.
>by your rationale, air would be denser as you go higher because of the
>decreased temperature.

The air does tend to be colder as altitude increases, and that does
make it denser than it would be if it were warmer. But the bigger
factor is that air density decreases with altitude, as you point out.

> economic flying at higher altitude is because
>the skin of the plane has less friction, not because the engine is
>finding it easier to suck in air.

If I was unclear on that, I apologize. The greater economy is due to
decreased air resistance. The engine does develop less power but the
main reason performance decreases is that lift decreases due to
thinner air.

> in fact, the opposite is true.
>that's where turbos & super charges come from - the need to increase air
>volume in aero engines at high altitude because air density is too low
>to produce needed power.

The turbo will help the engine overcome the loss of power, but
aircraft performance will still decrease due to the thinner air. It
may have higher true airspeed due to lower air resistance but a lower
rate of climb compared to sea level.

"jim beam" > wrote
> Elle wrote:
> > "jim beam" > wrote
> >
> >>and regarding lower mileage in the winter, one of the
> >
> > biggest factors is
> >
> >>a change in gas formulation. "winter" grades of gas
have
> >
> > lower
> >
> >>calorific content.
> >
> >
> > You have referred to this often. I finally googled. Does
> > this web site and its accompanying sites discuss what
you
> > mean?
> >
> > http://www.epa.gov/oms/rfg/whereyoulive.htm
> >
> > If so, the part of the country that uses this lower
calorie
> > fuel is extraordinarily geographically small. It's
certainly
> > not nationwide.
>
> it's nationwide and seasonal.

Baloney. Your own citation below does not say it's
nationwide. It indicates some areas use it: "Oxygenated
gasolines, which are required in some areas of the U.S.(see
Chapter 4, Oxygenated Gasoline), have lower heating
values... "

Further along, it hints that it may be used elsewhere, at
best.

You should be saying that local use of oxygenated gasoline
in some areas of the U.S. /may/ reduce fuel mileage.

> "The heating value of winter gasoline is
> about 1.5 percent lower than summer gasoline because
winter gasoline
> contains more volatile, less dense hydrocarbons."
>
http://www.chevron.com/products/prod.../bulletin/moto
rgas/1_driving-performance/pg4.asp#power
> i've cited this before.

> > Aside: Your refusal to snip posts to which you are
replying
> > and so repeat ad nauseam is rude. Very.
>
> go forth and multiply. a logical argument requires
retention of
> relevant points.

You include non-relevant points routinely. You also presume
people are incapable of looking back. Do whatever. Along
with your refusal to use caps so a reader can easily discern
sentences, your posts are a pain.

Whatever. Be an arse.

Elle wrote:
> "jim beam" > wrote
>
>>Elle wrote:
>>
>>>"jim beam" > wrote
>>>
>>>
>>>>and regarding lower mileage in the winter, one of the
>>>
>>>biggest factors is
>>>
>>>
>>>>a change in gas formulation. "winter" grades of gas
>
> have
>
>>>lower
>>>
>>>
>>>>calorific content.
>>>
>>>
>>>You have referred to this often. I finally googled. Does
>>>this web site and its accompanying sites discuss what
>
> you
>
>>>mean?
>>>
>>>http://www.epa.gov/oms/rfg/whereyoulive.htm
>>>
>>>If so, the part of the country that uses this lower
>
> calorie
>
>>>fuel is extraordinarily geographically small. It's
>
> certainly
>
>>>not nationwide.
>>
>>it's nationwide and seasonal.
>
>
> Baloney. Your own citation below does not say it's
> nationwide. It indicates some areas use it: "Oxygenated
> gasolines, which are required in some areas of the U.S.(see
> Chapter 4, Oxygenated Gasoline), have lower heating
> values... "
>
> Further along, it hints that it may be used elsewhere, at
> best.
>
> You should be saying that local use of oxygenated gasoline
> in some areas of the U.S. /may/ reduce fuel mileage.

er, the section on fuel economy has 3 paragraphs on factors that effect
economy, starting with calorific value and how calorific value is
seasonally adjusted. it /then/ goes on to discuss additional factors
such as oxygenation. such a device of argument is called "logical
progression".

>
>
>> "The heating value of winter gasoline is
>>about 1.5 percent lower than summer gasoline because
>
> winter gasoline
>
>>contains more volatile, less dense hydrocarbons."
>>
>
> http://www.chevron.com/products/prod.../bulletin/moto
> rgas/1_driving-performance/pg4.asp#power
>
>>i've cited this before.
>
>
>>>Aside: Your refusal to snip posts to which you are
>
> replying
>
>>>and so repeat ad nauseam is rude. Very.
>>
>>go forth and multiply. a logical argument requires
>
> retention of
>
>>relevant points.
>
>
> You include non-relevant points routinely. You also presume
> people are incapable of looking back. Do whatever. Along
> with your refusal to use caps so a reader can easily discern
> sentences, your posts are a pain.
>
> Whatever. Be an arse.
>
>
er, i leave relevant commentary in the name of logical progression...
ever heard of it? [rhetorical]

"jim beam" > wrote in message
...
> Elle wrote:
> > "jim beam" > wrote
> >
> >>Elle wrote:
> >>
> >>>"jim beam" > wrote
> >>>
> >>>
> >>>>and regarding lower mileage in the winter, one of the
> >>>
> >>>biggest factors is
> >>>
> >>>
> >>>>a change in gas formulation. "winter" grades of gas
> >
> > have
> >
> >>>lower
> >>>
> >>>
> >>>>calorific content.
> >>>
> >>>
> >>>You have referred to this often. I finally googled.
Does
> >>>this web site and its accompanying sites discuss what
> >
> > you
> >
> >>>mean?
> >>>
> >>>http://www.epa.gov/oms/rfg/whereyoulive.htm
> >>>
> >>>If so, the part of the country that uses this lower
> >
> > calorie
> >
> >>>fuel is extraordinarily geographically small. It's
> >
> > certainly
> >
> >>>not nationwide.
> >>
> >>it's nationwide and seasonal.
> >
> >
> > Baloney. Your own citation below does not say it's
> > nationwide. It indicates some areas use it: "Oxygenated
> > gasolines, which are required in some areas of the
U.S.(see
> > Chapter 4, Oxygenated Gasoline), have lower heating
> > values... "
> >
> > Further along, it hints that it may be used elsewhere,
at
> > best.
> >
> > You should be saying that local use of oxygenated
gasoline
> > in some areas of the U.S. /may/ reduce fuel mileage.
>
> er, the section on fuel economy has 3 paragraphs on
factors that effect
> economy, starting with calorific value and how calorific
value is
> seasonally adjusted. it /then/ goes on to discuss
additional factors
> such as oxygenation. such a device of argument is called
"logical
> progression".

You're being non-responsive, and when it comes to logic, you
don't know what you're talking about.

You should be saying that local use of oxygenated (yada)
gasoline in some areas of the U.S. /may/ reduce fuel
mileage.

> > You include non-relevant points routinely. You also
presume
> > people are incapable of looking back. Do whatever. Along
> > with your refusal to use caps so a reader can easily
discern
> > sentences, your posts are a pain.
> >
> > Whatever. Be an arse.
> >
> >
> er, i leave relevant commentary in the name of logical
progression...
> ever heard of it? [rhetorical]

Jim, I don't think you have a mind that thinks entirely
logically.

Or it's just incredibly poor writing on your part.

Elle
No need to bother snipping response to Jim's posts. Let him
suffer.

After all of that I forgot to say what I think we can discern from
aircraft performance that does relate to cars. The greatest factor
affecting airplanes at ground level (the realm of the automobile) is air
temperature. It affects the takeoff performance of airplanes so
drastically that air crews have to use charts to tell how much weight to
allow on the aircraft. In places that get really hot, sometimes they
don't even take off because they can't carry enough people and baggage
to make it worth the trip. The engines run great in any case, with a
small enough variance in performance that it's not really a factor. But
the density of the air has such a drastic effect on wings and propellers
that it becomes a safety issue.

As this relates to cars, I would guess that the greatest single factor
affecting the efficiency of winter driving would be incerased wind
resistance. Driving in snow probably doesn't help much either. But I
wouldn't expect that cold air would be a problem for the engine. In
fact, engines tend to produce more power in cold weather because they
take in more air. Not that this would affect a car engine because you
never run them at max power anyway.

"In fact, engines tend to produce more power in cold weather because
they
take in more air. Not that this would affect a car engine because you
never run them at max power anyway."

Also produces more torque, which always matters.

Misterbeets wrote:
>
> "In fact, engines tend to produce more power in cold weather because
> they
> take in more air. Not that this would affect a car engine because you
> never run them at max power anyway."
>
> Also produces more torque, which always matters.

That's a good point.

On Sun, 20 Nov 2005 12:11:07 -0600, Robbie and Laura Reynolds
> wrote:

>
>
>Gordon McGrew wrote:
>>
>> (Any pilot will tell you about the huge increase in performance of an
>> aircraft going from 70F to 0F. They will also tell you about the
>> increased economy of flying at higher altitude where air density - and
>> aircraft performance - is reduced.)
>
>This is a very unclear statement. There is a curved graph for aircraft
>efficiency that takes into account temperature and altitude. As
>altitude increases, air density decreases. Also, the temperature
>decreases, except above around 30 to 40 thousand feet, at which it stays
>almost constant at -65 F until there is not enough air to run an
>engine. Starting at sea level, it is more efficient to fly an airliner
>the higher you go because of decreased temperature and density until you
>get to 30,000 feet. Any higher than that is less efficient because of
>decreased density with no further decrease in temperature. This is why
>airliners fly at or near 30,000 feet.
>
>Obviously this altitude is above the max altitude attainable by small
>piston powered airplanes and the altitude/efficiency factor is therefore
>not relevant in the same way. When you simply say "airplanes" you
>confuse the issue. Most small airplanes don't have turbochargers,
>intercoolers, superchargers, or whatever, although they all have heated
>intakes to prevent ice. Lots of older large planes with radial engines
>have superchargers built into the back of the engine to pack in more
>air, as well as a heated intake to prevent ice. Apparently the
>resistance of denser air, as another poster mentioned, is not a
>problem. Incidentally, the ice forms as a result of the venturi effect,
>where the air speeds up and experiences decreased pressure and lower
>temperature as it goes past the carburetor venturi and draws gasoline
>into the intake. Jet engines really don't care about ice. They suck in
>a ton of air and use turbine blades to squish it down into an extremely
>small space, causing it to get very hot, and then the fuel is injected.
>
>Most of these factors affecting airplanes relate in no way to a car
>engine. Neither do altitude and efficiency and their effect on aircraft
>performance. The altitude, temperature and density that a car deals
>with is only the tip of the airplane iceberg.

I think that the confusion is that, when I speak of aircraft
performance I am speaking of its ability to climb which is improved by
denser air(colder and/or lower altitude.) This is true for all
aircraft with the possible exception of high performance military
aircraft which are almost rockets. Light aircraft are definitely more
fuel efficient at higher altitudes although they generally aren't
flying above 10,000 feet because that requires supplemental oxygen for
the pilot and passengers. Their performance (rate of climb) at higher
altitudes (or higher temperatures) is compromised not only by reduced
engine power but by reduced ability of the wings to generate lift in
less dense air. By 20,000 feet their performance (rate of climb) is
essentially zero. Turbocharging or supercharging will restore the
engine's power and allow them to climb further but the rate of climb
will still be much less than at sea level.

By the measure of true airspeed the picture is mixed. Reduced air
density reduces parasitic drag but also reduces engine power (in
atmospheric engines) so the net effect on true airspeed is not very
large. Fuel economy does improve however. Adding a turbo will make
the aircraft faster at high altitudes and it will still be more fuel
efficient than at sea level.

To bring it back to cars; increased air density will definitely
increase fuel consumption at higher speeds. Sea level air density at
0F is about 20% higher than at 80F and wind resistance would be
proportionately higher as well. Since wind resistance is the major
factor in fuel consumption at high speeds, it is obvious that highway
fuel economy will suffer significantly for this reason alone when the
temperature is cold. Warming the intake air will not help this.