Honda Car Forum

I have a 1999 Honda Accord LX six cylinder with about 31,000 miles on it. I
have always used unleaded gasoline 87 octane (manual says use 86 or higher)
and had no problems. However a friend of mine said I would get better
performance and mileage if I used premium grade higher octane gasoline.
Other than paying a higher price per gallon is there really any difference
in performance or mileage using higher octane fuel if the compression ratio
remains unchanged?
John

In article <LfWdncbEh56QCPGiXTWJjg@comcast.com>,
"John Shamblin" <jsham5@comcast.net> wrote:

> I have a 1999 Honda Accord LX six cylinder with about 31,000 miles on it. I
> have always used unleaded gasoline 87 octane (manual says use 86 or higher)
> and had no problems. However a friend of mine said I would get better
> performance and mileage if I used premium grade higher octane gasoline.

He's wrong.

Have him show us his degree in chemistry, and his certifications from
the auto engineering or petroleum industries. What? He doesn't have
any? Imagine that.

He's wrong.

In your case, there's no difference other than (a) you'll spend more
money, and (b) you'll actually get slightly *in*ferior gas mileage and
power due to the higher octane fuel's requirements for burning.

Do you know what octane is? Better yet, let's ask him. Does HE know
what octane is?

Octane is not a "power booster".

Hi,
Would you believe your friend's advice or the owner's manual?
Have money to burn? You said your car is running fine.
Tony

John Shamblin wrote:
> I have a 1999 Honda Accord LX six cylinder with about 31,000 miles on it. I
> have always used unleaded gasoline 87 octane (manual says use 86 or higher)
> and had no problems. However a friend of mine said I would get better
> performance and mileage if I used premium grade higher octane gasoline.
> Other than paying a higher price per gallon is there really any difference
> in performance or mileage using higher octane fuel if the compression ratio
> remains unchanged?
> John
>
>

"John Shamblin" <jsham5@comcast.net> wrote in message
news:LfWdncbEh56QCPGiXTWJjg@comcast.com...
> I have a 1999 Honda Accord LX six cylinder with about 31,000 miles on it.
I
> have always used unleaded gasoline 87 octane (manual says use 86 or
higher)
> and had no problems. However a friend of mine said I would get better
> performance and mileage if I used premium grade higher octane gasoline.

Apparently if you use the 93 oct gas, you get 10 extra hp from the new V6
240hp Honda engine, according to some Honda engineer. Not sure about better
mileage though. However, I haven't heard anything of this sort about the
older 200hp V6 engine. Personally, I'd stick with the 87 octane.

Cheers,

Pete

In article <bki6v1$qdr$1@news.onet.pl>,
"Pete" <escape2music@hotmail.com> wrote:

> Apparently if you use the 93 oct gas, you get 10 extra hp from the new V6
> 240hp Honda engine, according to some Honda engineer.

Ah, the net. Great source for random crap.

Other than this anonymous Honda engineer that no one has ever actually
seen or talked to, is there any other source for this? No, I didn't
think so.

And even if this were true, it would be true IF and ONLY IF the engine
control computer were designed specifically for this situation.

This guy's 99 Accord most definitely isn't designed for this.

"Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote in message
news:Eg1bb.89452$Yw.65623@fe03.atl2.webusenet.com. ..
> In article <bki6v1$qdr$1@news.onet.pl>,
> Other than this anonymous Honda engineer that no one has ever actually
> seen or talked to, is there any other source for this? No, I didn't
> think so.

Yup, it's pretty much a hearsay. I wouldn't bet my life on it, that's for
sure.


>
> And even if this were true, it would be true IF and ONLY IF the engine
> control computer were designed specifically for this situation.

It may be smart enough to adjust timing - many ECUs can do it these days.

>
> This guy's 99 Accord most definitely isn't designed for this.

Didn't I say it only applied to the new V6 (2003 and up)? ;-)

Cheers,

Pete

"Pete" <escape2music@hotmail.com> wrote in
news:bki9o7$2vj$1@news.onet.pl:

>
> "Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote in message
> news:Eg1bb.89452$Yw.65623@fe03.atl2.webusenet.com. ..
>> In article <bki6v1$qdr$1@news.onet.pl>,
>> Other than this anonymous Honda engineer that no one has ever
>> actually seen or talked to, is there any other source for this? No,
>> I didn't think so.
>
> Yup, it's pretty much a hearsay. I wouldn't bet my life on it, that's
> for sure.
>
>
>>
>> And even if this were true, it would be true IF and ONLY IF the
>> engine control computer were designed specifically for this
>> situation.
>
> It may be smart enough to adjust timing - many ECUs can do it these
> days.
>
>>
>> This guy's 99 Accord most definitely isn't designed for this.
>
> Didn't I say it only applied to the new V6 (2003 and up)? ;-)
>
> Cheers,
>
> Pete
>
>
>
>
>
VTEC The VT stands for variable timing. The 2003 models will adjust
themsleves to the octane used. Is 10hp worth $0.20+ per gallon? Not to
me. My V6 Accord runs just fine on 87.

"John Shamblin" <jsham5@comcast.net> wrote in
news:LfWdncbEh56QCPGiXTWJjg@comcast.com:

> I have a 1999 Honda Accord LX six cylinder with about 31,000 miles on
> it. I have always used unleaded gasoline 87 octane (manual says use
> 86 or higher) and had no problems. However a friend of mine said I
> would get better performance and mileage if I used premium grade
> higher octane gasoline. Other than paying a higher price per gallon is
> there really any difference in performance or mileage using higher
> octane fuel if the compression ratio remains unchanged?
> John
>
>

The Octane number means resistance to detonation.
Higher Octane does not mean higher energy content in the gasoline.

Some engines (for example the Mistubishi 6 cylinder), can adjust to higher
Octane gasoline. By using the knock sensor, they can sense the higher
Octane number, then advance the ingition or something that would give you
more HP.

AFAIK, the stock Honda engine cannot make use of higher Octane than 87.
Older, worn and/or modified engines MAY benefit from higher Octane. You may
want to try to switch gasoline and determine for yourself. YMMV.

In article <bki9o7$2vj$1@news.onet.pl>,
"Pete" <escape2music@hotmail.com> wrote:

> > And even if this were true, it would be true IF and ONLY IF the engine
> > control computer were designed specifically for this situation.
>
> It may be smart enough to adjust timing - many ECUs can do it these days.

But generally not in family haulers.

In article <Xns93FCA97E2E613paulcardozaattbicXm@206.127.4.25> ,
Paul Cardoza <paulcardoza@comcast.net> wrote:

> VTEC The VT stands for variable timing. The 2003 models will adjust
> themsleves to the octane used.

And just where is this documented?

It's not a feature of VTEC. If that were so, my 92 Civic Si would have
done that. And it didn't.

No, it's a feature of the engine control computer, pure and simple.
Nothing more, nothing less. It's how the computer is programmed to
respond to certain sensory inputs.

That the engine has variable valve timing and lift control doesn't mean
the computer that controls it was programmed to do anything with higher
octane fuel. The two have nothing to do with one another.

I'm still waiting for Honda documentation that says the 03 Accord V6
will advance its timing in response to higher octane fuel. So far, it's
just a net rumor. And you know what those are. They're like
opinions--and you know what THOSE are like.