Honda Car Forum

In article <3YOdnRaaVPeZcSPfRVn-3A@speakeasy.net>,
jim beam <nospam@example.net> wrote:

> i'm not interested in a personal disagreement - i'm only interested in
> the technology. i've stated what what i understand to be the current
> state of the art, and that /does/ include ability to run different
> grades of gas to best advantage.

The state of the art is that yes, that can be done. Does any car
company engineer that into its low end family car?

No.

jim beam <nospam@example.net> wrote in
news:i_WdnbHfUslmVCPfRVn-jA@speakeasy.net:

> Elmo P. Shagnasty wrote:
>> In article <1jfl1zo9zf0s1.dlg@ss.me-privacy-net.com>,
>> "S.S." <me@privacy.net> wrote:
>>
>>
>>>Just use the "Regular 87". Using higher octanes won't harm the
>>>engine, but it will definitely harm your wallet.
>>
>>
>> Higher octane fuel, in fact, will lead to *less* gas mileage for that
>> car.
>>
> not necessarily. depends how smart the engine management system is.



Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
of energy by volume than lower octanes.


--
TeGGeR®

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

TeGGeR® wrote:
> jim beam <nospam@example.net> wrote in
> news:i_WdnbHfUslmVCPfRVn-jA@speakeasy.net:
>
>
>>Elmo P. Shagnasty wrote:
>>
>>>In article <1jfl1zo9zf0s1.dlg@ss.me-privacy-net.com>,
>>> "S.S." <me@privacy.net> wrote:
>>>
>>>
>>>
>>>>Just use the "Regular 87". Using higher octanes won't harm the
>>>>engine, but it will definitely harm your wallet.
>>>
>>>
>>>Higher octane fuel, in fact, will lead to *less* gas mileage for that
>>>car.
>>>
>>
>>not necessarily. depends how smart the engine management system is.
>
>
>
>
> Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
> of energy by volume than lower octanes.
>
>
other way around, according to my bosch automotive handbook at any rate.
there, regular gasoline is rated at 42.7MJ/kg vs. premium at
43.5MJ/kg. at 1.054kJ per btu, that's...

In article <s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net>,
jim beam <nospam@example.net> wrote:

> > Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
> > of energy by volume than lower octanes.
> >
> >
> other way around, according to my bosch automotive handbook at any rate.

Your handbook is wrong.

In article <elmop-44A5C2.14285526062005@nntp1.usenetserver.com>,
"Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote:

> In article <3YOdnRaaVPeZcSPfRVn-3A@speakeasy.net>,
> jim beam <nospam@example.net> wrote:
>
> > i'm not interested in a personal disagreement - i'm only interested in
> > the technology. i've stated what what i understand to be the current
> > state of the art, and that /does/ include ability to run different
> > grades of gas to best advantage.
>
> The state of the art is that yes, that can be done. Does any car
> company engineer that into its low end family car?
>
> No.

For Honda, yes. It's not a matter of the ECU adapting to the fuel.
It's a matter of having simple feedback systems in key areas. Honda
knows how to make simple and efficient ECUs like nobody else.

That said, octane doesn't change performance unless the ECU is retarding
the ignition and recirculating exhaust gas to avoid knocking at wide
open throttle. The HAH does it all the time at low throttle but who
cares? Exhaust gas recirculation is just as good as more octane for low
throttle.

Elmo P. Shagnasty wrote:
> In article <s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net>,
> jim beam <nospam@example.net> wrote:
>
>
>>>Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
>>>of energy by volume than lower octanes.
>>>
>>>
>>
>>other way around, according to my bosch automotive handbook at any rate.
>
>
> Your handbook is wrong.
>

maybe, but the bosch automotive handbook has been an industry standard
for nearly 30 years. if it /is/ wrong, you really need to write & tell
them.

in addition,

http://www.chevron.com/products/prod.../fuel_economy/

contains the passage:

"On average, the heating value of premium-grade gasoline is about 0.7
percent higher than regular-grade because premium-grade, in general,
contains more aromatic hydrocarbons — the class of hydrocarbons with the
highest densities."

admittedly, that's not a lot, and chevron go on to say that the consumer
cannot tell the difference, but the principle applies. it's also
[engineering] ballpark with the bosch figues which show a 1.8%
differential. in either case, the difference does not justify the cost
increment.

in looking for that reference, i was surprised how hard it was to find
references to btu ratings for gasoline, because when you buy natural
gas, it's rated in btu's per cubic foot so there's no "black magic" on
what you're getting for your money. with gasoline, that information is
all but absent. i find that extroardinary because there's really /no/
reason it can't be smilarly rated. except perhaps that it would make
oil companies more accountable...

for california residents, there's also this little nugget:

http://www.chevron.com/products/prod...enrgycon.shtml

great. even less bang for the buck.

jim beam <nospam@example.net> wrote in
news:s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net:

> TeGGeR® wrote:

>>
>> Actually, Elmo's assertion is correct. Higher octane fuels have fewer
>> BTUs of energy by volume than lower octanes.
>>
>>
> other way around, according to my bosch automotive handbook at any
> rate.
> there, regular gasoline is rated at 42.7MJ/kg vs. premium at
> 43.5MJ/kg. at 1.054kJ per btu, that's...
>



That's an error.

Google for it.

--
TeGGeR®

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

On Sun, 26 Jun 2005 19:21:53 -0700, jim beam <nospam@example.net>
wrote:

>Elmo P. Shagnasty wrote:
>> In article <s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net>,
>> jim beam <nospam@example.net> wrote:
>>
>>
>>>>Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
>>>>of energy by volume than lower octanes.
>>>>
>>>>
>>>
>>>other way around, according to my bosch automotive handbook at any rate.
>>
>>
>> Your handbook is wrong.
>>
>
>maybe, but the bosch automotive handbook has been an industry standard
>for nearly 30 years. if it /is/ wrong, you really need to write & tell
>them.
>
>in addition,
>
>http://www.chevron.com/products/prod.../fuel_economy/
>
>contains the passage:
>
>"On average, the heating value of premium-grade gasoline is about 0.7
>percent higher than regular-grade because premium-grade, in general,
>contains more aromatic hydrocarbons — the class of hydrocarbons with the
>highest densities."
>
>admittedly, that's not a lot, and chevron go on to say that the consumer
>cannot tell the difference, but the principle applies. it's also
>[engineering] ballpark with the bosch figues which show a 1.8%
>differential. in either case, the difference does not justify the cost
>increment.
>
>in looking for that reference, i was surprised how hard it was to find
>references to btu ratings for gasoline, because when you buy natural
>gas, it's rated in btu's per cubic foot so there's no "black magic" on
>what you're getting for your money. with gasoline, that information is
>all but absent. i find that extroardinary because there's really /no/
>reason it can't be smilarly rated. except perhaps that it would make
>oil companies more accountable...
>
>for california residents, there's also this little nugget:
>
>http://www.chevron.com/products/prod...enrgycon.shtml
>
>great. even less bang for the buck.

Well you had to know that throwing some oxygen into the mix wasn't
going to give you more energy. Pre-burned fuel, what a marketing
concept.

Gordon McGrew wrote:

> On Sun, 26 Jun 2005 19:21:53 -0700, jim beam <nospam@example.net>
> wrote:
>
>
>>Elmo P. Shagnasty wrote:
>>
>>>In article <s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net>,
>>> jim beam <nospam@example.net> wrote:
>>>
>>>
>>>
>>>>>Actually, Elmo's assertion is correct. Higher octane fuels have fewer BTUs
>>>>>of energy by volume than lower octanes.
>>>>>
>>>>>
>>>>
>>>>other way around, according to my bosch automotive handbook at any rate.
>>>
>>>
>>>Your handbook is wrong.
>>>
>>
>>maybe, but the bosch automotive handbook has been an industry standard
>>for nearly 30 years. if it /is/ wrong, you really need to write & tell
>>them.
>>
>>in addition,
>>
>>http://www.chevron.com/products/prod.../fuel_economy/
>>
>>contains the passage:
>>
>>"On average, the heating value of premium-grade gasoline is about 0.7
>>percent higher than regular-grade because premium-grade, in general,
>>contains more aromatic hydrocarbons — the class of hydrocarbons with the
>>highest densities."
>>
>>admittedly, that's not a lot, and chevron go on to say that the consumer
>>cannot tell the difference, but the principle applies. it's also
>>[engineering] ballpark with the bosch figues which show a 1.8%
>>differential. in either case, the difference does not justify the cost
>>increment.
>>
>>in looking for that reference, i was surprised how hard it was to find
>>references to btu ratings for gasoline, because when you buy natural
>>gas, it's rated in btu's per cubic foot so there's no "black magic" on
>>what you're getting for your money. with gasoline, that information is
>>all but absent. i find that extroardinary because there's really /no/
>>reason it can't be smilarly rated. except perhaps that it would make
>>oil companies more accountable...
>>
>>for california residents, there's also this little nugget:
>>
>>http://www.chevron.com/products/prod...enrgycon.shtml
>>
>>great. even less bang for the buck.
>
> Well you had to know that throwing some oxygen into the mix wasn't
> going to give you more energy. Pre-burned fuel, what a marketing
> concept.

One of my great laughs was a few years ago when a drink salesman was at
my local deli and was pushing "Sports Water", i.e., water with extra O2.
I asked the guy how he differentiated it from hydrogen peroxide & got a
bovine stare.

"TeGGeR®" <tegger@tegger.c0m> wrote in
news:Xns9681E3D5F9995tegger@207.14.113.17:

> jim beam <nospam@example.net> wrote in
> news:s9SdnVGyi-cf1SLfRVn-gg@speakeasy.net:
>
>> TeGGeR® wrote:
>
>>>
>>> Actually, Elmo's assertion is correct. Higher octane fuels have fewer
>>> BTUs of energy by volume than lower octanes.
>>>
>>>
>> other way around, according to my bosch automotive handbook at any
>> rate.
>> there, regular gasoline is rated at 42.7MJ/kg vs. premium at
>> 43.5MJ/kg. at 1.054kJ per btu, that's...
>>
>
>
>
> That's an error.
>
> Google for it.
>



I just did some digging of my own to be sure. Basically, the energy content
is the same between different octane ratings of gas...UNLESS...oxygenates
have been used.

Oxygenates (alcohols, ethers) reduce the energy content of the fuel mixture
because they introduce more oxygen into the mix. As the O2 sensor responds
to the increased oxygen content, the engine management system will increase
fuel delivery to compensate, hence lower gas mileage.

This from the Gasoline FAQ and from Wikipedia.
www.repairfaq.org/filipg/AUTO/F_Gasoline2.html
http://en.wikipedia.org/wiki/Gasoline

I've noticed through extensive record keeping that my Integra will deliver
an average of 2% lower gas mileage with 91 octane versus 87. The 91 octane
I use has no oxygenates, and yet I still get a fuel mileage reduction.

--
TeGGeR®

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