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ok, so i went to fill up at the local BPAmoco station near me, and it wasnt until i had about 3/4 a tank full that their nozzles were labelled wrong!

i initially grabbed the nozzle that said 93 octane, but i didnt notice until later that the price listed was 87 octane!

ok, so i know going with a lower octane will result in reduced performance, but is 87 low enough to negate any safeties that the knock sensor is supposed to prevent?
 

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shouldnt be a problem...dont worry about it...drive along ....just fill up with 91+ from now on...i drove on 87 octane for a month when gas was really high
 

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I know around here that if the station was out of the 87 octane then they give you the premium for the same price, so maybe thats all it was!
 

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Take it easy until you use up the tank, that means not full throttle, and below 5000rpm.
 

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Your motor should detune for the the lower octane fuel...At least that's what it say's in the manuel..Won't hurt anything..
 

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Ho0k3d0nFoniCs on Mar/07/04 said:
shouldnt be a problem...dont worry about it...drive along ....just fill up with 91+ from now on...i drove on 87 octane for a month when gas was really high


Quote: Pawwalski on Mar/07/04
Yeah you should be fine. What I would do, is fill up everytime you hit 3/4ths of a tank with 93 octane.
you're batting a 1000....on guesses.

what do you base your "shouldn't be a problem" reply on?

the knock sensor cannot detect knock above 4000-4500 rpm since the engine noise is at the same amplitude and frequency of knocking.
 

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What about using a can of that "octane booster" in the stores. Even if you don't use the whole can.
 

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homeslice229 on Mar/07/04 said:
What about using a can of that "octane booster" in the stores. Even if you don't use the whole can.

my response to that, hehe...




Quote: br1t1shguy on Nov/09/03 The truth of octane booster is that it doesnt really boost octane as much as one might think. I beleive in fact that a bottle of the stuff can only add at the most 1-2 octane points. If I remember what my chem teacher told me correctly, it's to do with the fact that simply pouring toulene or another octane adding checmicl to a tank of gas is not very effective. I beleive the biggest difference is the chemicals used, most octane boosters are toulene etc, while when gas is made they use stuff like methyl tertiary butyl ether etc.


Quote: MichaelDelaney on Nov/21/02 Quote: integra04life on Nov/21/02...is it safe to put into our tegs? in a word: NO!!

it will cause faster carbon deposits build-up on your valves and piston domes leading eventually in a loss of burn efficiency and incomplete closing of the valves.

There's no good reason to add octane boost. If you are doing this for power, you have sadly been misled.

There was a nice thread here awhile back on why more expensive high octane gasoline doesn't add power. It only helps if you are misfiring. If you aren't, then don't add it. It will cause deposits on your engine internals from the impurities used in the octane boost.

[BTW, the Great Gasoline Debate thread was on the COMMoN TOPICS!!]

If you increase the octane of the gas when you are not misfiring , you only manage to shoot yourself in the foot by slowing the burn rate down past the point that is best for your engine. You actually LOSE power from a slower burn rate.

Increasing the octane only helps under specific conditions and doing it by adding octane boost rather than using the proper octane (R+M/2) gasoline is the worst way to do it . If you are not misfiring then forget this manoever...unless you like shooting your big toe off for kicks...hey, some people have weird fetishes...





Quote: MichaelDelaney on Nov/21/02 It improves emissions only if you weren't burning your fuel completely . In detonation, the risk is related to the fact that the mixture self-ignites by burning too quickly. Higher octane slows the burn rate down to achieve a more complete burn.

If you already were having an adequate burn rate without misfiring, adding octane boost would slow the normal burn rate down to a rate now that is TOO SLOW and NOT optimal. Now your thermodynamic efficiency is down:

You lose power and have worst emissions.

The reasons for wanting higher octane (because of misfiring) are listed in that Great Gasoline Debate thread in the Common Topics (top far right corner of the Performance Forum Page). Give it a read. You may actually become smarter because of it rather than being a gullible zombie slave to the commercials and sales pitches. Understanding WHY you do something rather than accepting the hype helps you make informed decisions.


Quote: MichaelDelaney on Oct/26/02 What about octane boost as opposed to using more expensive higher octane fuels? I don't recommend it. They do a number on your valves : one of nicest places for carbon deposits to stick to is the impure deposits from octane boost that cling to the valves and valve seats. Here's a nice discussion on a popular octane boost, toluene.



Quote: Eliot Lim Q: How did you discover using toluene?

A: Someone came across a web page that described various DIY home brew octane booster formulas. one of which used toluene as its main ingredient. As a Formula 1 racing fan of many years, I recalled that toluene was used extensively in the turbo era in the 1980s by all the Formula 1 teams. The 1.5 liter turbocharged engines ran as much as 5 bars of boost (73 psi) in qualifying and 4 bars (59 psi) in the actual race. Power output exceeded 1500bhp, which translates into 1000bhp/liter, an astronomical figure.

A motorsports journalist, Ian Bamsey, was able to obtain Honda's cooperation for his book "McLaren Honda Turbo, a Technical Appraisal". The book documents the key role that the toluene fuel played in allowing these tiny engines to run so much turbo boost without detonation. The term "rocket fuel" originated from the Formula 1 fraternity as an affectionate nickname to describe its devastating potency. Thus I concluded that I should focus my research on using toluene for my octane boosting project.

Individuals with good long term memory will recall that when unleaded gasoline was first introduced, only low octane grades were available. While it is not entirely clear that high octane super unleaded gas came about as a result of the advances in fuel technology in Formula 1, there is every reason to suspect that this is indeed the case, since many of the major oil companies were involved in the escalating race to develop increasingly potent racing fuel during this era.


Q: Why do you think toluene is better than other types of octane boosters?

A: Several reasons:

Mindful of the evil reputation of octane boosters in general, toluene is a very safe choice because it is one of the main octane boosters used by oil companies in producing ordinary gasoline of all grades. Thus if toluene is indeed harmful to your engine as feared, your engine would have disintegrated long, long ago since ordinary pump gasoline can contain as much as 50% aromatic hydrocarbons.

Toluene is a pure hydrocarbon (C7H8). i.e. it contains only hydrogen and carbon atoms. It belongs to a particular category of hydrocarbons called aromatic hydrocarbons. Complete combustion of toluene yields CO2 and H2O. This fact ensures that the entire emission control system such as the catalyst and oxygen sensor of your car is unaffected. There are no metallic compounds (lead, magnesium etc), no nitro compounds and no oxygen atoms in toluene. It is made up of exactly the same ingredients as ordinary gasoline. In fact it is one of the main ingredients of gasoline.

Toluene has a RoN octane rating of 121 and a MoN rating of 107, leading to a (R+M)/2 rating of 114. (R+M)/2 is how ordinary fuels are rated in the US. Note that toluene has a sensitivity rating of 121-107=14. This compares favorably with alcohols which have sensitivities in the 20-30 range. The more sensitive a fuel is the more its performance degrades under load. Toluene's low sensitivity means that it is an excellent fuel for a heavily loaded engine.

Toluene is denser than ordinary gasoline (0.87 g/mL vs. 0.72-0.74) and contains more energy per unit volume. Thus combustion of toluene leads to more energy being liberated and thus more power generated. This is in contrast to oxygenated octane boosters like ethanol or MTBE which contain less energy per unit volume compared to gasoline. The higher heating value of toluene also means that the exhaust gases contain more kinetic energy, which in turn means that there is more energy to drive turbocharger vanes. In practical terms this is experienced as a faster onset of turbo boost.

Chevron's published composition of 100 octane aviation fuel shows that toluene comprises up to 14% alone and is the predominant aromatic hydrocarbon. Unfortunately composition specifications for automotive gasoline is harder to pin down due to constantly changing requirements.

Chevron's web site also describes the problems of ethanol being used in gasoline.

MTBE was heavily touted as a clean additive several years ago, and became a key ingredient in reformulated gasoline that is sold in California. But recently new studies arose that showed that MTBE was far more toxic than previously imagined. Organizations such as oxybusters have formed around the country to eliminate the use of MTBE in gasoline and several states, including California have passed new laws to eventually outlaw MTBE.


Q: How much toluene should I use per tank of gas?

A: Octane ratings can be very easily calculated by simple averaging. For example, the tank of an Audi A4 1.8TQ is 15.6 gallons. Filling it with 14.6 gallons of 92 octane and 1 gallon of toluene (114 octane) will yield a fuel mix of:

(14.6 * 92) + (1 * 114) / 15.6 = 93.4

The Audi A4 1.8T is a good example of a car that has very high octane needs if it has been modified to produce more turbo boost. The base compression ratio of this car is a very high 9.5:1 and when an additional 1 bar (14.7 psi) of turbo boost is applied on top of it, the resulting effective compression ratio is way beyond what 92 or 93 octane fuel can ever hope to cope with. Most modified 1.8Ts running without octane enhancement are running with severely retarded ignition timing and boost.


Q: Will toluene damage my engine or other parts of my car?

A: A 5 or 10% increase in the aromatic content of gas will most likely be well within the refining specifications of gasoline defined by ASTM D4814, which specify an aromatic content of between 20% and 45%. What this means is that if the 92 octane gas that you started off with had an aromatic content of say 30% and you increased it by 10% to 40% you would still be left with a mix that meets the industry definition of gasoline. So the above question would amount to: "Will gasoline damage my engine or other parts of my car?"

Even in the unlikely event that the 92 octane gas has a aromatic content of 45% the resulting mix would still be within the bounds of gasoline sold in other countries.


Q: Isn't toluene an extremely toxic substance?

A: The common perception of toluene's toxicity far exceeds reality. Fortunately there is an ample body of information available that specifically addresses this question. Toluene is more toxic than gasoline but it is certainly not agent orange or cyanide.

US Environmental Protection Agency Chemical Summary

US Agency for Toxic Substances and Disease Registry (ATSDR)

National priority list of toxic substances
Note that the ATSDR also rates gasoline as a hazardous substance.

Mobil's spec sheet for toluene even goes as far as saying that "Based on available toxicological information, it has been determined that this product poses no significant health risk when used and handled properly."


Q: Isn't toluene an active ingredient of TNT (trinitrotoluene) and is thus deadly?

A: In the same way that cotton wool is the base ingredient of nitrocellulose (guncotton) which in turn is the main ingredient in modern smokeless gunpowder. Using this reasoning one could conclude that cotton wool is a deadly substance. This question reflects a poor understanding of basic chemistry but unfortunately it has been asked often enough.


Q: How much does toluene cost, and where can I buy some?

A: $10/gallon in a one gallon can at a hardware store, about $6/gallon in a 5 gallon can from a chemical supply or paint store, or $3/gallon in a 55 gallon drum from a chemical supply warehouse.


Q: Can I just dump in 100% toluene into the tank like the F1 racers? vroom vroom vroom

A: First of all, the F1 racers did not use 100% toluene, but 84%. The other 16% in their brew is n-heptane, which has an octane rating of zero. The reason for this strange combination is because the F1 rocket fuel was limited to the rules to being of 102 RoN octane. The n-heptane is "filler" to make the fuel comply with the rules.

Because toluene is such an effective anti knock fuel it also means that it is more difficult to ignite at low temperatures. The Formula 1 cars that ran on 84% toluene needed to have hot radiator air diverted to heat its fuel tank to 70C to assist its vaporization. Thus too strong a concentration of toluene will lead to poor cold start and running characteristics. I recommend that the concentration of toluene used to not exceed what the engine is capable of utilizing. i.e. Experiment with small increases in concentration until you can no longer detect an improvement.

Q: Ok, what is the catch?

A: It should be mentioned that in the US, efforts are underway to reduce the aromatic content of gasolines in general as a higher aromatic content leads to higher benzene emissions. Benzene is an extremely toxic substance. However it should also be noted that the proportions that is being discussed in this FAQ is relatively small and in the grand scheme of things is probably insignificant. Moreover, the industrial standard for defining gasoline composition allows plenty of leeway in aromatic content and the proportions present in US gas is already lower than most other countries. I therefore feel that the information provided here is useful to a performance minded car enthusiast while not being significantly detrimental to the environment.
 

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Matt_Of_MI on Mar/07/04 said:
Quote: ajinct on Mar/07/04
around here some gas station have 103 is it ok for me to use that stuff or what


do you not read at all? or is it ignorance?
I think the previous post was too long for him.
 

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hardbagel on Mar/07/04 said:
it was long
yet very informative and if you could take the time to read it you could learn alot of intresting facts and information that i never knew before.. now i can tell my friends why octane booster is bad..they are always like man im gonna go buy some octane booster and whooop your a$$
 

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Matt_Of_MI on Mar/07/04 said:
long but very informative. if you're too lazy to learn then there is not much hope for you
agreed. If you don't have the attention span to read and learn don't ask for a shorter version. Just accept the fact that you won't learn anything, and go on being uninformed and waste money on things that you don't about.
 

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for a bone-stock b18c1 (which it looks like he has from his info), i don't see the big problem.

read your manual; honda says it's ok.

just don't do it again b/c you do have a loss of performance... also from the manual.
 
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