Ok i was reading this

http://www.honduh.com/showthre...=3820

They said the 91 octane hinders a stock car performance(stock Accord). Is this true cuz i run 93 on my 98 Accord. I wanted to check on here since this is the real deal on H-T. That other site covers nothing but 6th gen accords.

 

yes, its true. 98+ honduh Accords are made to use 87 octane (my PoS v6 anyway). anything more than that, the compression isnt high enough to completely burn the fuel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Legendaryyaj &raquo;</TD></TR><TR><TD CLASS="quote">
They said the 91 octane hinders a stock car performance(stock Accord). Is this true cuz i run 93 on my 98 Accord. </TD></TR></TABLE>
No, it's not true. The only difference between a fuels octane rating is it's resistance to detonation. (and price.)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
No, it's not true. The only difference between a fuels octane rating is it's resistance to detonation. (and price.) </TD></TR></TABLE>

So which is it ?

I've always used 93.

When I use 87 it seems to not run as well. It might be psychological.

Some proof would be great.

 

When I was running 89 bare minimum octane fuel and even with my current mods I noticed I would only get about 280-300 miles to a tank, now with 91 I am getting close to 315-340 depending on how I drive. My mods are intake,exhaust, and ecu upgrade. Not a whole lot but I do notice a little bit of power difference between the 89 and 91.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">

So which is it ?

I've always used 93.

When I use 87 it seems to not run as well. It might be psychological.

Some proof would be great.
</TD></TR></TABLE>

I thought lower octane would do more harm, and plus it does run shittier. So does anyone have any facts to prove it right or wrong.

 

about 2 years car and driver did dyno testing with cars using 87 and 91 octane. the cars the required 91, according the owners manual, made more power than on 87. the one car the tested that required 87, the 6th V6 accord, made less power on 91 than 87.

the key is to use what the manifacturer reccomends. using premium fuel on a F series is a waste unless you have advanced the ignition timing to take advantage of the resistence to detontation or your running some sort of FI. if you place 87 in a stock F series and then put in 91, it will not make anymore power and possibly make less. if it's making more power through your butt dyno it's most likely the placebo effect.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chiovnidca &raquo;</TD></TR><TR><TD CLASS="quote">
No, it's not true. The only difference between a fuels octane rating is it's resistance to detonation. (and price.) </TD></TR></TABLE>
I thought the difference was in how clean it burns. In turn cleaner burning fuel would equal a cleaner and smoother performance, RIGHT?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Legendaryyaj &raquo;</TD></TR><TR><TD CLASS="quote">I thought the difference was in how clean it burns. In turn cleaner burning fuel would equal a cleaner and smoother performance, RIGHT?</TD></TR></TABLE>Sometimes high-octane gasoline has better cleaners, but that's NOT what OCTANE means.

Higher octane resists detonation better. If your combustion chamber design combined with spark timing, etc, doesn't need the higher octane, then it won't do you any good. In that case the only advantage of higher octane is that someone gets more of your money...

 

In reality.. the higher octane number (as someone said earlier) reduces the chance of detonation on a higher compression motor. By the same token, the higher octane fuel burns MORE slowly than lower octane fuel.

As a result, those running 93 in a car with low compression tend to produce more carbon buildup in their intake manifold and valve chamber.

But I would love to see that dyno you're talking about in Car & Driver. I've read alot of C&D magazines and have never once seen them post a dyno plot in it...

Still an interesting point, but like I said earlier, I would like to "see" proof.

Thanks for all the replies.

 

I know im my turbo F22 if i run 93 i can tell a difference in the A/F ratios and the way my car idles a tad unlike my 94 octane i run(im skeeered of detonation). This really doesnt apply to me because im FI but what does concern me is the quality of the gas, thats another thing youd have to factor in( i only buy Sunoco but if i someone could tell me some other places im all aboot it).

 

I remember that C&D article, too. The cars were all stock, I think. The ones that required high-octane saw a big difference when you put regular in.

But the ones that needed regular, when you put in high-octane, there was barely any difference at all. I remember the Accord being slightly worse, some others being slightly better. But the difference in all of these was so small that it seemed to be within the measurement uncertainty.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Escobar &raquo;</TD></TR><TR><TD CLASS="quote">In reality.. the higher octane number (as someone said earlier) reduces the chance of detonation on a higher compression motor. By the same token, the higher octane fuel burns MORE slowly than lower octane fuel.

As a result, those running 93 in a car with low compression tend to produce more carbon buildup in their intake manifold and valve chamber.

But I would love to see that dyno you're talking about in Car & Driver. I've read alot of C&D magazines and have never once seen them post a dyno plot in it...

Still an interesting point, but like I said earlier, I would like to "see" proof.

Thanks for all the replies.
</TD></TR></TABLE>

Here is the C&D article's dyno.

 

ok, im switching to 87 octane now. bye bye 93 til i boost.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zeta_msz_006 &raquo;</TD></TR><TR><TD CLASS="quote">

Here is the C&D article's dyno.
</TD></TR></TABLE>
That doesn't mean anything, post the rest of the article and you'll see they did the dyno runs on two different days. Weather conditions can cause the difference.

 

ok here to all you kings and queens...
when you take fuel and compress it...they will get hot. high octane rating fuel resistance to pre-mature explosion in the conbustion chamber or known as detonation. what does this mean? high compression engine needs high octane fuel to prevent pre-mature explosion in the chamber...that's why gsr and prelude vtec needs high octane fuel and integra LS and accords dont..cuz their compression is not high...and also notice prelude and gsr have knock sensor while accord and tegra dont..(there's more others)
so high octane on a car that doesn't need it is actually not good for the motor.

 

if the car is design to run 87, stick with the cheaper gas.

the car wouldnt go into limp mode for the 87rated octane(unlike a h22a prelude)

 

This was coverd a few times already
6th gen Accords stay with regular
7th gen Accords premium gain power