E. Meyer wrote:
>
>
> On 4/24/09 9:02 AM, in article gsrvcr.1sk.0@poczta.onet.pl, "Pszemol"
> <Pszemol@PolBox.com> wrote:
>
>> BTW - is there any reason at all for running Civic on mid grade gas?
>> This engine was designed to run on regular, so there is no knoking
>> which can be avoided using higher octane gasoline...
>>
>
> They all have knock sensors that will make any knocking immediately
> disappear, probably before you even notice that its doing it, regardless of
> what gas you use vs. what was actually spec'd for the car.
>
> There was some traffic from Honda several years ago that indicated some of
> the cars were actually designed for premium fuel and would give better
> mileage and performance if it is used, but rated for regular and depended on
> the knock sensor to make it all work.
>
> The way to find out if yours is one of those is to run several tanks of
> higher octane fuel in it. If the mileage is consistently better then you
> can benefit from it. If it isn't, stick with regular. AFAIK, all the
> Civics are designed for regular.
>

Believe me, I started using midgrade reluctantly. This car has
freakishly high gearing, and I first started using it so I'd be less
likely to stall it starting out in first on hills. (And no, I'm no
newbie to standard transmissions. Between the tall gearing and the idle
being set at 600, the car really is touchy.) It worked, and I also
noticed a 10% increase in economy. Since midgrade gas was/is only about
5% more expensive, it made sense to keep using it. The thing about knock
sensors is they only stop knocking - they don't increase performance. In
fact, they are there so the engine can run a more advanced timing curve
when you use higher octane gas. This Civic is the only car I've had that
got better MPG on midgrade.

 

Leftie <No@Thanks.net> wrote in news:d8oIl.35465$gC1.24884@newsfe19.iad:

> E. Meyer wrote:
>>
>>
>> On 4/24/09 9:02 AM, in article gsrvcr.1sk.0@poczta.onet.pl, "Pszemol"
>> <Pszemol@PolBox.com> wrote:
>>
>>> BTW - is there any reason at all for running Civic on mid grade gas?
>>> This engine was designed to run on regular, so there is no knoking
>>> which can be avoided using higher octane gasoline...
>>>
>>
>> They all have knock sensors that will make any knocking immediately
>> disappear, probably before you even notice that its doing it,
>> regardless of what gas you use vs. what was actually spec'd for the
>> car.
>>
>> There was some traffic from Honda several years ago that indicated
>> some of the cars were actually designed for premium fuel and would
>> give better mileage and performance if it is used, but rated for
>> regular and depended on the knock sensor to make it all work.
>>
>> The way to find out if yours is one of those is to run several tanks
>> of higher octane fuel in it. If the mileage is consistently better
>> then you can benefit from it. If it isn't, stick with regular.
>> AFAIK, all the Civics are designed for regular.
>>
>
> Believe me, I started using midgrade reluctantly. This car has
> freakishly high gearing, and I first started using it so I'd be less
> likely to stall it starting out in first on hills. (And no, I'm no
> newbie to standard transmissions. Between the tall gearing and the
> idle being set at 600, the car really is touchy.) It worked, and I
> also noticed a 10% increase in economy. Since midgrade gas was/is only
> about 5% more expensive, it made sense to keep using it. The thing
> about knock sensors is they only stop knocking - they don't increase
> performance. In fact, they are there so the engine can run a more
> advanced timing curve when you use higher octane gas. This Civic is
> the only car I've had that got better MPG on midgrade.





Your car has identical low gearing and final drive to all other Civics
prior to it. But your 4th and 5th are in fact higher than they used to
be, probably to help improve Honda's CAFE numbers.
(I do very much wish _my_ 4th and 5th were higher than they are...)

If you DON'T have the D15Z1 engine, no-load idle of 600rpm is too low.

Pump octanes have zero effect on whether an engine is more or less
easily stalled at lights. If there is any effect at all, it's a
perceived one, not an actual one.

Boosting the octane rating of gasoline serves only one purpose: to
prevent the tendency of a fuel/air mix to self-combust all at once in
the absence of a controlled flame front. Self-combustion is what's known
as "knocking". On its own, higher octanes have no other meaningful
effect on engine performance.

Engine control systems are only capable of increasing performance with
higher octanes if they are designed to do so. Your Civic's is not. The
Civic is designed for 87 pump octane. Its engine management is not
capable of advancing timing past designed-in limits that do not take
higher octanes into account, but can only /retard/ timing if knocking is
sensed.

Your knock sensor is intended to decrease the tendency to knock, not
/specifically/ to prevent engine damage, but to decrease emissions of
nitric oxide (NO) while still maintaining the best power and mileage
that can be achieved without engine damage.

I've conducted my own fairly extensive tests of different octanes. Given
that testing of any meaningful length of time necessarily involves
seasonal temperature changes, my results were inconclusive. If anything,
I got a very slight /reduction/ in mileage with 91 pump octane versus
87.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

In article <d8oIl.35465$gC1.24884@newsfe19.iad>, Leftie <No@Thanks.net>
wrote:

> The thing about knock
> sensors is they only stop knocking - they don't increase performance. In
> fact, they are there so the engine can run a more advanced timing curve
> when you use higher octane gas.

No, that's not why they're there.

Knock sensors are there so that when you use a gasoline that does NOT
have the anti-knock properties that are called for in the
gasoline--let's say you used a lower octane gas--then the engine doesn't
detonate.

But when the engine is already designed for 87 octane fuel, and if
you're using a proper 87 octane fuel (not **** water), then the knock
sensors don't come into play at all. (I am ignoring the effects of age
and bad maintenance causing carbon buildup inside the combustion
chamber, which would lead to knocking with 87 octane fuel, which means
that a higher octane fuel will help. Rather, I am discussing a properly
maintained and clean engine.)

Again, the knock sensors don't come into play at all. You can put all
the higher octane gas you want in, and the knock sensors don't move the
timing around to keep the engine just at the point of knock. No, the
knock sensing system is designed to work with fuels lower than what the
engine was designed for. The system was NOT designed to advance timing
in the presence of higher octane fuels that are beyond the octane rating
specified by the engineers.

 

Elmo P. Shagnasty wrote:
> In article <d8oIl.35465$gC1.24884@newsfe19.iad>, Leftie <No@Thanks.net>
> wrote:
>
>> The thing about knock
>> sensors is they only stop knocking - they don't increase performance. In
>> fact, they are there so the engine can run a more advanced timing curve
>> when you use higher octane gas.
>
> No, that's not why they're there.
>
> Knock sensors are there so that when you use a gasoline that does NOT
> have the anti-knock properties that are called for in the
> gasoline--let's say you used a lower octane gas--then the engine doesn't
> detonate.
>
> But when the engine is already designed for 87 octane fuel, and if
> you're using a proper 87 octane fuel (not **** water), then the knock
> sensors don't come into play at all. (I am ignoring the effects of age
> and bad maintenance causing carbon buildup inside the combustion
> chamber, which would lead to knocking with 87 octane fuel, which means
> that a higher octane fuel will help. Rather, I am discussing a properly
> maintained and clean engine.)
>
> Again, the knock sensors don't come into play at all. You can put all
> the higher octane gas you want in, and the knock sensors don't move the
> timing around to keep the engine just at the point of knock. No, the
> knock sensing system is designed to work with fuels lower than what the
> engine was designed for. The system was NOT designed to advance timing
> in the presence of higher octane fuels that are beyond the octane rating
> specified by the engineers.

well, the truth is between the two of you. knock sensors allow the
motor to run the most advanced curve it can without knock, regardless of
fuel. at the edge of the envelope, knock can vary tank to tank, rainy
days, vs. non-rainy days, cold, hot, etc. if you can figure out where
the knock point is, you can move timing accordingly. if you don't know,
you just have to set it back, and leave a safety margin. that means
very slightly less power and/or fuel economy. in this day and age of
powerful engine computers, there's no reason not to pursue that marginal
improvement.

 

Tegger wrote:
> Leftie <No@Thanks.net> wrote in news:d8oIl.35465$gC1.24884@newsfe19.iad:
>
>> E. Meyer wrote:
>>>
>>> On 4/24/09 9:02 AM, in article gsrvcr.1sk.0@poczta.onet.pl, "Pszemol"
>>> <Pszemol@PolBox.com> wrote:
>>>
>>>> BTW - is there any reason at all for running Civic on mid grade gas?
>>>> This engine was designed to run on regular, so there is no knoking
>>>> which can be avoided using higher octane gasoline...
>>>>
>>> They all have knock sensors that will make any knocking immediately
>>> disappear, probably before you even notice that its doing it,
>>> regardless of what gas you use vs. what was actually spec'd for the
>>> car.
>>>
>>> There was some traffic from Honda several years ago that indicated
>>> some of the cars were actually designed for premium fuel and would
>>> give better mileage and performance if it is used, but rated for
>>> regular and depended on the knock sensor to make it all work.
>>>
>>> The way to find out if yours is one of those is to run several tanks
>>> of higher octane fuel in it. If the mileage is consistently better
>>> then you can benefit from it. If it isn't, stick with regular.
>>> AFAIK, all the Civics are designed for regular.
>>>
>> Believe me, I started using midgrade reluctantly. This car has
>> freakishly high gearing, and I first started using it so I'd be less
>> likely to stall it starting out in first on hills. (And no, I'm no
>> newbie to standard transmissions. Between the tall gearing and the
>> idle being set at 600, the car really is touchy.) It worked, and I
>> also noticed a 10% increase in economy. Since midgrade gas was/is only
>> about 5% more expensive, it made sense to keep using it. The thing
>> about knock sensors is they only stop knocking - they don't increase
>> performance. In fact, they are there so the engine can run a more
>> advanced timing curve when you use higher octane gas. This Civic is
>> the only car I've had that got better MPG on midgrade.
>
>
>
>
>
> Your car has identical low gearing and final drive to all other Civics
> prior to it. But your 4th and 5th are in fact higher than they used to
> be, probably to help improve Honda's CAFE numbers.
> (I do very much wish _my_ 4th and 5th were higher than they are...)
>
> If you DON'T have the D15Z1 engine, no-load idle of 600rpm is too low.
>
> Pump octanes have zero effect on whether an engine is more or less
> easily stalled at lights. If there is any effect at all, it's a
> perceived one, not an actual one.
>
> Boosting the octane rating of gasoline serves only one purpose: to
> prevent the tendency of a fuel/air mix to self-combust all at once in
> the absence of a controlled flame front. Self-combustion is what's known
> as "knocking". On its own, higher octanes have no other meaningful
> effect on engine performance.
>
> Engine control systems are only capable of increasing performance with
> higher octanes if they are designed to do so. Your Civic's is not. The
> Civic is designed for 87 pump octane. Its engine management is not
> capable of advancing timing past designed-in limits that do not take
> higher octanes into account, but can only /retard/ timing if knocking is
> sensed.
>
> Your knock sensor is intended to decrease the tendency to knock, not
> /specifically/ to prevent engine damage, but to decrease emissions of
> nitric oxide (NO) while still maintaining the best power and mileage
> that can be achieved without engine damage.
>
> I've conducted my own fairly extensive tests of different octanes. Given
> that testing of any meaningful length of time necessarily involves
> seasonal temperature changes, my results were inconclusive. If anything,
> I got a very slight /reduction/ in mileage with 91 pump octane versus
> 87.
>
>
>

Interesting. A few points: I had a problem with stalling when
starting off going up inclines, not at lights. That has improved,
possibly just from the midgrade cleaning the injectors. As for the
increase in fuel economy, that's real. And there is a white line across
my tach right at about 600 RPM; it's obviously there to tell owners that
the low idle is intentional. What's the D15Z1 engine? I suspect I may
have it. Finally, I wouldn't mind having two overdrives (4th and 5th)
but *third* is also way too tall. Trying to accelerate up a hill in
third, even after revving the bejesus out of it in second, is
discouraging. My 91Hp series one Si would kick this car''s 126hp *** on
the dragstrip. Still, as long as it keeps getting 40+mpg in Summer, I'll
live with it.

 

Elmo P. Shagnasty wrote:
> In article <d8oIl.35465$gC1.24884@newsfe19.iad>, Leftie <No@Thanks.net>
> wrote:
>
>> The thing about knock
>> sensors is they only stop knocking - they don't increase performance. In
>> fact, they are there so the engine can run a more advanced timing curve
>> when you use higher octane gas.
>
> No, that's not why they're there.
>
> Knock sensors are there so that when you use a gasoline that does NOT
> have the anti-knock properties that are called for in the
> gasoline--let's say you used a lower octane gas--then the engine doesn't
> detonate.
>
> But when the engine is already designed for 87 octane fuel, and if
> you're using a proper 87 octane fuel (not **** water), then the knock
> sensors don't come into play at all. (I am ignoring the effects of age
> and bad maintenance causing carbon buildup inside the combustion
> chamber, which would lead to knocking with 87 octane fuel, which means
> that a higher octane fuel will help. Rather, I am discussing a properly
> maintained and clean engine.)
>
> Again, the knock sensors don't come into play at all. You can put all
> the higher octane gas you want in, and the knock sensors don't move the
> timing around to keep the engine just at the point of knock. No, the
> knock sensing system is designed to work with fuels lower than what the
> engine was designed for. The system was NOT designed to advance timing
> in the presence of higher octane fuels that are beyond the octane rating
> specified by the engineers.


There is a contradiction being promoted here: that my car is
designed for 87 octane gas only, and that it has knock sensors in case I
use gas below 87 octane - below Regular grade. Perhaps Honda doesn't
respect American gasoline? BTW, my Civic Si also did better power-wise
on midgrade (but with worse fuel economy), and IIRC it noted that higher
octane gas was preferred in the manual.

 

Leftie <No@Thanks.net> wrote in
news:q6yIl.113971$qO1.59271@newsfe13.iad:

> Elmo P. Shagnasty wrote:

>>
>> Again, the knock sensors don't come into play at all. You can put
>> all the higher octane gas you want in, and the knock sensors don't
>> move the timing around to keep the engine just at the point of knock.
>> No, the knock sensing system is designed to work with fuels lower
>> than what the engine was designed for. The system was NOT designed
>> to advance timing in the presence of higher octane fuels that are
>> beyond the octane rating specified by the engineers.
>
>
> There is a contradiction being promoted here: that my car is
> designed for 87 octane gas only, and that it has knock sensors in case
> I use gas below 87 octane - below Regular grade.



Not quite. It is possible to have gas that's nominally 87, but is
contaminated, of substandard quality or has degraded with age.

In any case, the primary purpose of the knock sensor is EMISSIONS, not
engine damage. Protection against engine damage does allow the computer to
advance the timing as far as it can without risking detonation, but it can
only go up to its designed-in limits, which are configured for 87 octane.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

Tegger wrote:
> Leftie <No@Thanks.net> wrote in
> news:q6yIl.113971$qO1.59271@newsfe13.iad:
>
>> Elmo P. Shagnasty wrote:
>
>>> Again, the knock sensors don't come into play at all. You can put
>>> all the higher octane gas you want in, and the knock sensors don't
>>> move the timing around to keep the engine just at the point of knock.
>>> No, the knock sensing system is designed to work with fuels lower
>>> than what the engine was designed for. The system was NOT designed
>>> to advance timing in the presence of higher octane fuels that are
>>> beyond the octane rating specified by the engineers.
>>
>> There is a contradiction being promoted here: that my car is
>> designed for 87 octane gas only, and that it has knock sensors in case
>> I use gas below 87 octane - below Regular grade.
>
>
>
> Not quite. It is possible to have gas that's nominally 87, but is
> contaminated, of substandard quality or has degraded with age.
>
> In any case, the primary purpose of the knock sensor is EMISSIONS, not
> engine damage.

not necessarily true. the more advanced, the more NOx because
combustion temp is higher. but the trade is better fuel economy and/or
power. thus, in an ideal world, you want the ignition as advanced as
possible for any given day, and the only way to determine the max limit
is to use knock detection.


> Protection against engine damage does allow the computer to
> advance the timing as far as it can without risking detonation, but it can
> only go up to its designed-in limits, which are configured for 87 octane.

modern ignition timing algorithms, for want of a better word, are highly
advanced.

http://www.google.com/patents?id=Dto...J&dq=5,038,736

 

In article <tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net>,
jim beam <retard-finger@bad.example.net> wrote:

> modern ignition timing algorithms, for want of a better word, are highly
> advanced.

<rimshot>

Thank you, thank you. He's here all week, folks.

 

jim beam <retard-finger@bad.example.net> wrote in
news:tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net:

> Tegger wrote:
>> Leftie <No@Thanks.net> wrote in
>> news:q6yIl.113971$qO1.59271@newsfe13.iad:
>>
>>> Elmo P. Shagnasty wrote:
>>
>>>> Again, the knock sensors don't come into play at all. You can put
>>>> all the higher octane gas you want in, and the knock sensors don't
>>>> move the timing around to keep the engine just at the point of
>>>> knock.
>>>> No, the knock sensing system is designed to work with fuels lower
>>>> than what the engine was designed for. The system was NOT designed
>>>> to advance timing in the presence of higher octane fuels that are
>>>> beyond the octane rating specified by the engineers.
>>>
>>> There is a contradiction being promoted here: that my car is
>>> designed for 87 octane gas only, and that it has knock sensors in
>>> case I use gas below 87 octane - below Regular grade.
>>
>>
>>
>> Not quite. It is possible to have gas that's nominally 87, but is
>> contaminated, of substandard quality or has degraded with age.
>>
>> In any case, the primary purpose of the knock sensor is EMISSIONS,
>> not engine damage.
>
> not necessarily true. the more advanced, the more NOx because
> combustion temp is higher. but the trade is better fuel economy
> and/or power. thus, in an ideal world, you want the ignition as
> advanced as possible for any given day, and the only way to determine
> the max limit is to use knock detection.



You're absolutely correct.

But even very slight knocking that would cause no damage to the engine
will dramatically increase NO emissions. Knock sensors, once rare,
became ubiquitous as part of the OBD-II emissions management system.




>
>
>> Protection against engine damage does allow the computer to
>> advance the timing as far as it can without risking detonation, but
>> it can only go up to its designed-in limits, which are configured for
>> 87 octane.
>
> modern ignition timing algorithms, for want of a better word, are
> highly advanced.
>
> http://www.google.com/patents?id=Dto...J&dq=5,038,736
>
>


Bedtime reading, anyone? I was fine until I got to the flowcharts. :^(



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

"Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote in
news:elmop-38F92B.12370925042009@mara100-84.onlink.net:

> In article <tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net>,
> jim beam <retard-finger@bad.example.net> wrote:
>
>> modern ignition timing algorithms, for want of a better word, are
>> highly advanced.
>
> <rimshot>
>
> Thank you, thank you. He's here all week, folks.
>



Is there an intermission? I'm out of popcorn.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

 

Anyone driving a coupe or sedan that gets less than 35 mpg is a leach
on society.

 

<honda.lioness@gmail.com> wrote in message
news:e30b4f2b-c43f-4f86-9da5-9efb77fbc04a@l16g2000pra.googlegroups.com...
> Anyone driving a coupe or sedan that gets less than 35 mpg
> is a leach on society.

You are so ridiculous...

Why 35mpg and not 55mpg?
Because your junky honda happens to be just over 35 line?

I drive 2004 honda accord coupe...
In what way am I a leach on society more than you are?

At least I am not cheating Carfax to get my fee back...

 

"Pszemol" <Psze...@PolBox.com> wrote:
> <honda.lion...@gmail.com> wrote in message

> > Anyone driving a coupe or sedan that gets less than 35 mpg
> > is a leach on society.
>
> You are so ridiculous...
>
> Why 35mpg and not 55mpg?

Because 35 is easily obtained today.

> Because your junky honda happens to be just over 35 line?

You have not seen my Honda.

> I drive 2004 honda accord coupe...
> In what way am I a leach on society more than you are?

It was written partly tongue in cheek, as a partial response to by
someone else that this is about what God intended. ;-)

> At least I am not cheating Carfax to get my fee back...

? You have the wrong person.

 

In article
<33f30032-a6bf-418b-b223-3eb36ce41db5@n7g2000prc.googlegroups.com>,
honda.lioness@gmail.com wrote:

> > Why 35mpg and not 55mpg?
>
> Because 35 is easily obtained today.

Then why aren't you on a scooter that gets 65mpg?

Oh, I see--YOU get to set the qualifications for what KIND of car people
should be driving, and--interestingly enough--that would be YOUR car.

Nothing more, nothing less.

Go ahead, put your money where your mouth is--buy a scooter and quit
being a "leach" (sweetheart, you meant "leech") on society.