Airfilters and milage.

Far be it from me to rehash old threads, (yeah, right) but I was
just flipping through a Consumer Report mag and read this little blurb
under "Myth Busters" beside an article on bettering fuel mileage. I
don't remember who said what, but CR says this:

"A dirty air filter. Our tests show that driving with a dirty air
filter no longer has any impact on fuel economy as it did with older
engines. This is because modern engines use computers to precisely
control the air/fuel mixture."

Now *I* still think a clogged filter will make the engine work
harder, but apparently it would have to be *REALLY* clog to make a
noticeable difference in your fuel mileage.
--


"You wouldn't know acceptable behavior, let alone 'nice',
if it bit you on your pudgy ankles." - Sam Trap

"WindsorFox<SS>" > wrote
but CR says this:
>
> "A dirty air filter. Our tests show that driving with a dirty air filter
> no longer has any impact on fuel economy as it did with older engines.
> This is because modern engines use computers to precisely control the
> air/fuel mixture."
>
> Now *I* still think a clogged filter will make the engine work harder,
> but apparently it would have to be *REALLY* clog to make a noticeable
> difference in your fuel mileage.

Heck, if you think about it, the fuel efficiency should get better since
more air equals more fuel equals more power. Well with a REALLY dirty filter
there's less air, so the 'puter sends less fuel. Voila'. <sarcasm off> lol

Scott W.
'68 Ranchero 500
'69 Mustang Sportsroof
TS #57. (anyone still using these?)

Modern engines are Mass Air Flow engines... they measure how much air
actually makes it into the engine. A severely restricted filter is going to
affect maximum power available but, for many driving circumstances, is going
to be pretty much "transparent".

Older speed/density systems would compute the amount of air taken in by the
motor using the MAP sensor and engine rpm (along with, more than likely,
TPS).

People sometimes expect that one size fits all... they can't do it with
pantyhose... how can we expect them to do it with something a little more
complex?

Top postingly yours...


"WindsorFox<SS>" > wrote in message
...
> Far be it from me to rehash old threads, (yeah, right) but I was just
> flipping through a Consumer Report mag and read this little blurb under
> "Myth Busters" beside an article on bettering fuel mileage. I don't
> remember who said what, but CR says this:
>
> "A dirty air filter. Our tests show that driving with a dirty air filter
> no longer has any impact on fuel economy as it did with older engines.
> This is because modern engines use computers to precisely control the
> air/fuel mixture."
>
> Now *I* still think a clogged filter will make the engine work harder,
> but apparently it would have to be *REALLY* clog to make a noticeable
> difference in your fuel mileage.
> --
>
>
> "You wouldn't know acceptable behavior, let alone 'nice',
> if it bit you on your pudgy ankles." - Sam Trap

"Jim Warman" > wrote in message
news:arL0k.472$7B3.8@edtnps91...
> Modern engines are Mass Air Flow engines... they measure how much air
> actually makes it into the engine. A severely restricted filter is going
> to affect maximum power available but, for many driving circumstances, is
> going to be pretty much "transparent".
>
> Older speed/density systems would compute the amount of air taken in by
> the motor using the MAP sensor and engine rpm (along with, more than
> likely, TPS).
>
> People sometimes expect that one size fits all... they can't do it with
> pantyhose... how can we expect them to do it with something a little more
> complex?
>
> Top postingly yours...

Saw this on CNN last night - a few minutes of "Myth Busting" with the
Consumer Reports rep. Bottom line, the dirty air filter won't make a
noticeable difference in the way the engine runs, except under heavy
acceleration. While fuel mileage will not suffer, performance will.

Keep changing out those air filters.

dwight

WindsorFox<SS> wrote:
> Far be it from me to rehash old threads, (yeah, right) but I was just
> flipping through a Consumer Report mag and read this little blurb under
> "Myth Busters" beside an article on bettering fuel mileage. I don't
> remember who said what, but CR says this:
>
> "A dirty air filter. Our tests show that driving with a dirty air
> filter no longer has any impact on fuel economy as it did with older
> engines. This is because modern engines use computers to precisely
> control the air/fuel mixture."
>
> Now *I* still think a clogged filter will make the engine work harder,
> but apparently it would have to be *REALLY* clog to make a noticeable
> difference in your fuel mileage.

I don't totally disagree to a point. If the filter is mildly dirty then
the difference in mileage is small. However, if the filter is dirty
enough to move the sensor data out the operating range of the computer
programs operating parameters then it will reduce mileage.

Scott W. wrote:
> "WindsorFox<SS>" > wrote
> but CR says this:
>> "A dirty air filter. Our tests show that driving with a dirty air filter
>> no longer has any impact on fuel economy as it did with older engines.
>> This is because modern engines use computers to precisely control the
>> air/fuel mixture."
>>
>> Now *I* still think a clogged filter will make the engine work harder,
>> but apparently it would have to be *REALLY* clog to make a noticeable
>> difference in your fuel mileage.
>
> Heck, if you think about it, the fuel efficiency should get better since
> more air equals more fuel equals more power. Well with a REALLY dirty filter
> there's less air, so the 'puter sends less fuel. Voila'. <sarcasm off> lol
>

Gee, in that case a restricter plate over the intake should double
my mileage.

--


"You wouldn't know acceptable behavior, let alone 'nice',
if it bit you on your pudgy ankles." - Sam Trap

Jim Warman wrote:
> Modern engines are Mass Air Flow engines... they measure how much air
> actually makes it into the engine. A severely restricted filter is going to
> affect maximum power available but, for many driving circumstances, is going
> to be pretty much "transparent".
>
> Older speed/density systems would compute the amount of air taken in by the
> motor using the MAP sensor and engine rpm (along with, more than likely,
> TPS).
>
> People sometimes expect that one size fits all... they can't do it with
> pantyhose... how can we expect them to do it with something a little more
> complex?
>
> Top postingly yours...
>
>
> "WindsorFox<SS>" > wrote in message
> ...
>> Far be it from me to rehash old threads, (yeah, right) but I was just
>> flipping through a Consumer Report mag and read this little blurb under
>> "Myth Busters" beside an article on bettering fuel mileage. I don't
>> remember who said what, but CR says this:
>>
>> "A dirty air filter. Our tests show that driving with a dirty air filter
>> no longer has any impact on fuel economy as it did with older engines.
>> This is because modern engines use computers to precisely control the
>> air/fuel mixture."
>>
>> Now *I* still think a clogged filter will make the engine work harder,
>> but apparently it would have to be *REALLY* clog to make a noticeable
>> difference in your fuel mileage.
>> --
>>
>>
>> "You wouldn't know acceptable behavior, let alone 'nice',
>> if it bit you on your pudgy ankles." - Sam Trap
>
>


What?? Where's the message??

--


"You wouldn't know acceptable behavior, let alone 'nice',
if it bit you on your pudgy ankles." - Sam Trap

"Michael Johnson" > wrote in message
...
> WindsorFox<SS> wrote:
>> Far be it from me to rehash old threads, (yeah, right) but I was just
>> flipping through a Consumer Report mag and read this little blurb under
>> "Myth Busters" beside an article on bettering fuel mileage. I don't
>> remember who said what, but CR says this:
>>
>> "A dirty air filter. Our tests show that driving with a dirty air
>> filter no longer has any impact on fuel economy as it did with older
>> engines. This is because modern engines use computers to precisely
>> control the air/fuel mixture."
>>
>> Now *I* still think a clogged filter will make the engine work harder,
>> but apparently it would have to be *REALLY* clog to make a noticeable
>> difference in your fuel mileage.
>
> I don't totally disagree to a point. If the filter is mildly dirty then
> the difference in mileage is small. However, if the filter is dirty
> enough to move the sensor data out the operating range of the computer
> programs operating parameters then it will reduce mileage.

If the filter is that dirty, it will set the check engine light. The effect
of a reasonably dirty air filter on fuel economy of a modern fuel injected
engine is so close to zero as to be zero.

To affect fuel mileage in a measurable way, the filter would have to be
practically plugged. Except at wide open throttle the air filter is not even
close to the most restrictive element in the intake tract (the throttle
plate is). For all practical purposes, there is no difference between a
partially plugged air filter and a partially close throttle.

A plugged filter can reduce maximum power, but the effect on fuel economy is
no different than a partially closed throttle (again talking about modern
fuel injected engines).

Ed

----- Original Message -----
From: "WindsorFox<SS>" >
Newsgroups: rec.autos.makers.ford.mustang
Sent: Monday, June 02, 2008 11:10 AM
Subject: Airfilters and milage.


> Scott W. wrote:
>> "WindsorFox<SS>" > wrote
>> but CR says this:
>>> "A dirty air filter. Our tests show that driving with a dirty air
>>> filter no longer has any impact on fuel economy as it did with older
>>> engines. This is because modern engines use computers to precisely
>>> control the air/fuel mixture."
>>>
>>> Now *I* still think a clogged filter will make the engine work harder,
>>> but apparently it would have to be *REALLY* clog to make a noticeable
>>> difference in your fuel mileage.
>>
>> Heck, if you think about it, the fuel efficiency should get better since
>> more air equals more fuel equals more power. Well with a REALLY dirty
>> filter there's less air, so the 'puter sends less fuel. Voila'. <sarcasm
>> off> lol
>>
>
> Gee, in that case a restricter plate over the intake should double my
> mileage.

A block of wood under the accelerator pedal will have the same affect and is
easier to install. A partially plugged air filter is the same as a partially
closed throttle.... (assuming we are talking about modern fuel injected
engines).

Ed

C. E. White wrote:
> "Michael Johnson" > wrote in message
> ...
>> WindsorFox<SS> wrote:
>>> Far be it from me to rehash old threads, (yeah, right) but I was just
>>> flipping through a Consumer Report mag and read this little blurb under
>>> "Myth Busters" beside an article on bettering fuel mileage. I don't
>>> remember who said what, but CR says this:
>>>
>>> "A dirty air filter. Our tests show that driving with a dirty air
>>> filter no longer has any impact on fuel economy as it did with older
>>> engines. This is because modern engines use computers to precisely
>>> control the air/fuel mixture."
>>>
>>> Now *I* still think a clogged filter will make the engine work harder,
>>> but apparently it would have to be *REALLY* clog to make a noticeable
>>> difference in your fuel mileage.
>> I don't totally disagree to a point. If the filter is mildly dirty then
>> the difference in mileage is small. However, if the filter is dirty
>> enough to move the sensor data out the operating range of the computer
>> programs operating parameters then it will reduce mileage.
>
> If the filter is that dirty, it will set the check engine light. The effect
> of a reasonably dirty air filter on fuel economy of a modern fuel injected
> engine is so close to zero as to be zero.
>
> To affect fuel mileage in a measurable way, the filter would have to be
> practically plugged. Except at wide open throttle the air filter is not even
> close to the most restrictive element in the intake tract (the throttle
> plate is). For all practical purposes, there is no difference between a
> partially plugged air filter and a partially close throttle.
>
> A plugged filter can reduce maximum power, but the effect on fuel economy is
> no different than a partially closed throttle (again talking about modern
> fuel injected engines).

Ed, we already beat this horse into hamburger.