Matt Ion

mvl_groups_user@yahoo.com wrote:

> Back in the 80's I remember my dad telling me that the most fuel
> efficient speed to drive his car was at 45 mph, and that it was a spec
> that was published for many car models.
>
> With the gas price absurdity these days, I'm just curious if is there
> an equivalent most efficient speed for today's cars? (Specifically my
> 05 EX-4 accord)

Actually, you can also find the R&T article here:
http://www.roadandtrack.com/article....&page_number=2


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gsl

if i drive 70-90km/hr in my 04 civic (automatic tranny) i usually get
50-55 mpg consistantly

On 29 Aug 2005 18:34:38 -0700, mvl_groups_user@yahoo.com wrote:

>Back in the 80's I remember my dad telling me that the most fuel
>efficient speed to drive his car was at 45 mph, and that it was a spec
>that was published for many car models.
>
>With the gas price absurdity these days, I'm just curious if is there
>an equivalent most efficient speed for today's cars? (Specifically my
>05 EX-4 accord)
>
>-MVL

Doug McCrary

gsl <novascrollerNOSPAM@ns.sympatico.ca> wrote in message
news:t80jh1pk6s6slocrm0cd0dftpuiriemgf4@4ax.com...
> if i drive 70-90km/hr in my 04 civic (automatic tranny) i usually get
> 50-55 mpg consistantly
>
> On 29 Aug 2005 18:34:38 -0700, mvl_groups_user@yahoo.com wrote:
>
> >Back in the 80's I remember my dad telling me that the most fuel
> >efficient speed to drive his car was at 45 mph, and that it was a spec
> >that was published for many car models.
> >
> >With the gas price absurdity these days, I'm just curious if is there
> >an equivalent most efficient speed for today's cars? (Specifically my
> >05 EX-4 accord)
> >
> >-MVL
>
You drive in kmph and figure distance/fuel unit in mpg?

gsl

yeah, canadians sorta use a combination of the 2 systems. or at
least i do.

On Sun, 04 Sep 2005 03:50:49 GMT, "Doug McCrary"
<DougMcCrary@spamcop.net> wrote:

>
>gsl <novascrollerNOSPAM@ns.sympatico.ca> wrote in message
>news:t80jh1pk6s6slocrm0cd0dftpuiriemgf4@4ax.com.. .
>> if i drive 70-90km/hr in my 04 civic (automatic tranny) i usually get
>> 50-55 mpg consistantly
>>
>> On 29 Aug 2005 18:34:38 -0700, mvl_groups_user@yahoo.com wrote:
>>
>> >Back in the 80's I remember my dad telling me that the most fuel
>> >efficient speed to drive his car was at 45 mph, and that it was a spec
>> >that was published for many car models.
>> >
>> >With the gas price absurdity these days, I'm just curious if is there
>> >an equivalent most efficient speed for today's cars? (Specifically my
>> >05 EX-4 accord)
>> >
>> >-MVL
>>
>You drive in kmph and figure distance/fuel unit in mpg?
>

mvl_groups_user@yahoo.com

I communte through many stop lights and stop signs each day. I've been
looking for the most fuel efficient acceleration for my 05 Accord (4
cyl).

I've seen posts saying that cars in general drive most efficiently if
driven near peak torque RPM, which for the accord is around 4500. My
car's an auto, so I don't have too much control over RPM's. But the
automatic likes to hover around 2000 RPMs, so the only way to be close
to 4500 is almost flooring the starts.

But I've also heard that the harder starts are less fuel efficient.
Based on the Nav MPG, I think I've found keeping RPM's under 2000
(sloooow acceleration) is more efficient.

I don't mind speed of acceleration, since my commute is on 1-lane roads
where no one can pass, and regardless of how fast I drive, I just get
stuck behind another car at the next stop light.

Anyone able to comment one way or the other on hard vs. soft
acceleration?

-MVL

Elliot Richmond

On 22 Sep 2005 04:45:03 -0700, mvl_groups_user@yahoo.com wrote:

>I communte through many stop lights and stop signs each day. I've been
>looking for the most fuel efficient acceleration for my 05 Accord (4
>cyl).
>
Back when cars had carburetors, hard acceleration would reduce fuel
efficiency, because the accelerator pump in the carburetor would
squirt extra fuel into the carburetor each time the accelerator was
depressed. You could see the wasted fuel blow out of the exhaust pipe
as blaclk smoke.

With modern fuel injected cars, that does not happen. Instead, the
computer constantly adjusts the fuel mixture to the optimum ratio,
depending on engine speed and throttle setting. So I really don't
think it matters a whole lot.

A couple of years ago I read an article that suggested, based on
computer models, that is was better to accelerate the fuel injected
car up to cruising speed relatively quickly (not flooring it!),
because that would mean less time spent with a richer fuel/air mixture
and thus less total fuel expended. But that was a computer simulation,
not real world driving.



Elliot Richmond
Freelance Science Writer and Editor

jim beam

Elliot Richmond wrote:
> On 22 Sep 2005 04:45:03 -0700, mvl_groups_user@yahoo.com wrote:
>
>
>>I communte through many stop lights and stop signs each day. I've been
>>looking for the most fuel efficient acceleration for my 05 Accord (4
>>cyl).
>>
>
> Back when cars had carburetors, hard acceleration would reduce fuel
> efficiency, because the accelerator pump in the carburetor would
> squirt extra fuel into the carburetor each time the accelerator was
> depressed. You could see the wasted fuel blow out of the exhaust pipe
> as blaclk smoke.

on a p.o.s. detroit hunkohunk, sure. today, that still happens, but to
a lesser degree because it's more precise /and/ catalysts take the sting
out of the visuals for you.

>
> With modern fuel injected cars, that does not happen.

yes it does - enrichment prevents flame-out. that's why it was done
with carburetted cars. and why it's still done with injected cars.
check out the megasquirt diy injector kit and read the source code if
you don't believe it.

> Instead, the
> computer constantly adjusts the fuel mixture to the optimum ratio,
> depending on engine speed and throttle setting.

including enrichment on acceleration!

> So I really don't
> think it matters a whole lot.
>
> A couple of years ago I read an article that suggested, based on
> computer models, that is was better to accelerate the fuel injected
> car up to cruising speed relatively quickly (not flooring it!),
> because that would mean less time spent with a richer fuel/air mixture
> and thus less total fuel expended. But that was a computer simulation,
> not real world driving.
>
>
>
> Elliot Richmond
> Freelance Science Writer and Editor

Jason

In article <1127389503.140080.167680@o13g2000cwo.googlegroups .com>,
mvl_groups_user@yahoo.com wrote:

> I communte through many stop lights and stop signs each day. I've been
> looking for the most fuel efficient acceleration for my 05 Accord (4
> cyl).
>
> I've seen posts saying that cars in general drive most efficiently if
> driven near peak torque RPM, which for the accord is around 4500. My
> car's an auto, so I don't have too much control over RPM's. But the
> automatic likes to hover around 2000 RPMs, so the only way to be close
> to 4500 is almost flooring the starts.
>
> But I've also heard that the harder starts are less fuel efficient.
> Based on the Nav MPG, I think I've found keeping RPM's under 2000
> (sloooow acceleration) is more efficient.
>
> I don't mind speed of acceleration, since my commute is on 1-lane roads
> where no one can pass, and regardless of how fast I drive, I just get
> stuck behind another car at the next stop light.
>
> Anyone able to comment one way or the other on hard vs. soft
> acceleration?
>
> -MVL

MVL,
There are two car mechanics that have a column in many different
newspapers. They wrote a column on this subject several months ago. They
stated that an engine will last much longer if you have slow starts from
stop signs and stop lights. I don't remember whether or not they discussed
gas mileage related to this subject. I don't advise you to have a slow
start related to getting on freeways or interstates. In most cases, it's
best to have fast starts--for safety reasons when getting on freeways and
interstates. I hate it when people--especially really old people--try to
get on freeways on interstates while going at a really low speed.

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Alan Browne

mvl_groups_user@yahoo.com wrote:
> I communte through many stop lights and stop signs each day. I've been
> looking for the most fuel efficient acceleration for my 05 Accord (4
> cyl).
>
> I've seen posts saying that cars in general drive most efficiently if
> driven near peak torque RPM, which for the accord is around 4500. My
> car's an auto, so I don't have too much control over RPM's. But the
> automatic likes to hover around 2000 RPMs, so the only way to be close
> to 4500 is almost flooring the starts.

Per Consumer Reports, some years ago, a "brisk" but not hard
acceleration is most fuel efficient. Slow accelerations are not
efficient either.

I have a manual transmission so I try to accelerate in 4000 - 5000 range.

If you're flooring the starts, there is no way it is more efficient than
what the transmission is automatically doing.

Cheers,
Alan

JXStern

On 22 Sep 2005 04:45:03 -0700, mvl_groups_user@yahoo.com wrote:
>Anyone able to comment one way or the other on hard vs. soft
>acceleration?

Downhill is good.

If you drive an Accord (with automatic) so that the tach even gets
momentarily to peak torque around 4500, you're going to be moving very
brisquely.

Which seems to mean that Honda thinks rather leisurely acceleration is
preferable, engine staying below 3k

J.