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Discussion Starter · #1 ·
Any knowledge if higher octanes are safe for the Quad? For a single tank?

Signed up for the WannaGoFast even in Dallas April 14-15 and would love to show up with 100+ octane fuel and see if I can beat 144mph in the 1/2 mile, which seems to be the limit of the stock Quad.

Anyone know of specific reasons why or why not a single tank of 100+ octane fuel would be safe or unsafe? Can't find much on it in the Google Machine, still looking though.

All recommendations and suggestions welcome, thanks all!!>:)
 

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The extra octane won't hurt anything. Just make sure it's actually unleaded fuel. Some of that race gas had lead in it, the lead will destroy your catalytic converter.

Your car isn't setup to take advantage of the extra octane, so you won't make any extra power. What you will be doing is wasting a whole bunch of money though.
 

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Discussion Starter · #3 · (Edited)
The extra octane won't hurt anything. Just make sure it's actually unleaded fuel. Some of that race gas had lead in it, the lead will destroy your catalytic converter. Your car isn't setup to take advantage of the extra octane, so you won't make any extra power. What you will be doing is wasting a whole bunch of money though.
Well, crapcakes, thanks for the lesson. Oh well, nevermind... Can I delete this thread? ;)
 

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Couple of things to note here:

Higher octane does not automatically equal higher power. Octane is simply a measure of the resistance againast detonation during compression. Basically, the higher octane fuel allows the cars computer to maintain the timing adjustment at the maximum power point longer. The result of this depends on how the computer is set up, and was shown a number of years ago when a magazine tested two cars rated for regular gas on a dunk and then tested them with premium. The Honda Accord (I-4)made slightly less power on higher octane, the Ford Mustang (V-6) made slight more power on the premium gas.

Simply filling up with 105 octane won’t give you 105 octane gas, because of residual gas in the system. Let’s say you toss in 105 octane gas on top of a half tank of premium (93 octane here). Since you’d add around 9-10 gallons, you’d end up with a mix of about 103-103.5 octane, in the tank. You’ll also have to allow for running for a while to get all that weak premium out of the pump and lines and let the new stuff trickle through.

Most “racing” fuel either lack or have smaller amounts of the additives added to commercial fuels like detergents and such.

High octane fuels require various esoteric additives to boost octane, some of which may damage parts of your emissions system.

We don’t know what level of adaptation that Alfa allowed in their programming, but even if you did use the higher octane, the computer would still start to retard timing to avoid knock based upon previous performance until it had time to learn it didn’t have to. Modern engine computers learning is pretty advanced.


If you feel the need, a commercial octane boost additive is your best compromise. Otherwise, Shell V-Power consistently shows the best results of the name major brand fuels. Simply start fueling with V-Power a couple of tanks before the event and you should get pretty much the best level of performance.
 

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When I saw this thread, I thought it was going to be another more octane is always better post.

I am glad to see Racer Z and AlfaCrisis spoke up with correct information. You wouldn't believe how badly this subject sometimes goes on other forums.

Greg
 

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When I saw this thread, I thought it was going to be another more octane is always better post.

I am glad to see Racer Z and AlfaCrisis spoke up with correct information. You wouldn't believe how badly this subject sometimes goes on other forums.

Greg
its "more better" for the guy selling it:wink2:
Shell V is probably the best gas available to us w/93...anything more is just not doing anything...
you want to clean your injectors use Techron has always worked for me:grin2:
 

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'we don't know what level of adaption"

true, but it's reasonable to expect commercially available at filling stations in their planned markets would be the parameters they would work with.
 

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Why is Cali Different??

I noticed that when I was in Cali last month the Shell stations showed 91 as the highest octane...is that regional or statewide???
 

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We switch blends to/from low volatility every year.
 

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Well, crapcakes, thanks for the lesson. Oh well, nevermind... Can I delete this thread? ;)
You can't delete it, but I can. I won't because it actually has useful information in it starting with a very good question.


I noticed that when I was in Cali last month the Shell stations showed 91 as the highest octane...is that regional or statewide???
Right, the best we have here is 91 octane. I suppose the next logical question is, "Will the car take advantage of the extra 2 octane?"

Even if it can, will that be enough more power to make a noticeable difference?
 

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"a noticeable difference"

probably not with a modern car that's plenty fast anyway - but with an old car with fixed timing, especially if underpowered so you stood on it often, yeah, you'd notice the pinging from bad gas, or a big hill etc and have to adjust the timing or back off to compensate. of course if your timing was already set for low octane, you wouldn't notice if you put in better fuel.

if you switched to the lower octane at a track where you actually are pushing it, you might notice.
 

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I noticed that when I was in Cali last month the Shell stations showed 91 as the highest octane...is that regional or statewide???
In Idaho it's 91 as well. Washington state it's 92.
 

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CA has their own mandated special supposedly less polluting blends, but I think it's just an excuse by the state to make gas more expensive for a worse product because they hate cars.
Let me rephrase:

CA has its own mandated less polluting blends, but I think it's just an excuse by the oil companies to make gas more expensive for a better product because we love cars but we love our environment more.
 

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Let me rephrase:

CA has its own mandated less polluting blends, but I think it's just an excuse by the oil companies to make gas more expensive for a better product because we love cars but we love our environment more.
Excuse or not, we do have more fuel additives here in SoCal than anywhere else, and the highest prices too. The extra additives are to help the fuel burn completely, keep the combustion chamber from building up with carbon, and probably a few other things.

Something is working here that is cleaning the air. Thirty years ago I could not see the Hollywood sign from where I live, it was a rare occasion the I could see the San Gabriel Mountains, and, from the top of Mount Wilson I could not see Los Angles - only the tops of the skyscrapers sticking up through the sea of smog.

Now, I can see the Hollywood sign very clearly on most days, fifteen miles away. I can see the San Gabriel Mountains most of the time, about eighty miles away. Driving Angeles Crest Highway up to Mount Wilson and looking down into the LA Basin, I can clearly see ALL of the city and outer lining basin. Just the other day we driving along the Pacific Coast enjoying the view of Catalina Island, which was about fifty miles away from us at the time.
 

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"a noticeable difference"

probably not with a modern car that's plenty fast anyway - but with an old car with fixed timing, especially if underpowered so you stood on it often, yeah, you'd notice the pinging from bad gas, or a big hill etc and have to adjust the timing or back off to compensate. of course if your timing was already set for low octane, you wouldn't notice if you put in better fuel.

if you switched to the lower octane at a track where you actually are pushing it, you might notice.
Right. Pre-ignition, also known as 'ping' or 'knock' is a major problem that can destroy a perfectly good engine. The higher the octane, the more compression the engine can run. More compression equals more power. Octane is not power, just the ability to control when the gasoline ignites.

Modern engines with knock sensors will retard the ignition timing to reduce knocking. Using higher octane fuel will allow the engine to use maximum timing advance, up to the limit the factory allows. They built the engine to run on 'pump gas', or 91 octane. They did not allow for 105 octane fuel.

To build an engine that creates the compression required, that 105 octane would be required, would cost a whole lot of money, and you'd have to have an aftermarket ECU that's user programmable. Just to toss numbers around, I'd start with $30,000 USD as a starting point, to build the existing engine. Yes, you'd have power coming out your ears, and you'd probably get 12 MPG and definitely would not pass a smog test. You'd loose the reliability and longevity of the stock engine too. But, you could brag about how your two liter has twice the power, 280 x 2 = 560.
 

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"less polluting blends"
I do believe that these blends pollute less only when being transferred from the pump to the tank, that they simply don't evaporate as easily - I could be wrong on this as I've been away from local publications a few years. But I do expect that anything the fuel might contribute is more than offset by pot fumes, or spreading campfires of the homeless along the 405.

LA was terrible - but the two primary reasons for the improvement are chasing all the manufacturing that was in that trapped valley of smoke into different states or country's. They don't make much of anything in LA anymore except video games, and it used to be a mecca for manufacturing, large and small. The other big improvement would be the 02 sensor, which allows for proper fuel management and extremely clean combustion, and of course far better performance. I have no doubt that would have been implemented anyway, just as every other improvement in fuel and ignition management was. The catalytic converter was important before the 02 sensor, but really doesn't do much now except turn naturally occurring trace pollutants into a modified chemical structure which pollutes at least as badly, while encouraging shoddy mining and manufacturing in countries with no standards.

Last time we bought a new car there the state offered us the opportunity to bribe them directly to avoid the first smog check - which should point out that the program is about revenue at this point. The proverbial beater gardening truck, a daily driven commercial vehicle, is largely exempt from testing due to the age of the chosen vehicles. Poor people with newer vehicles are exempt from repairs through a hardship provision.

As much as it has improved since the early 70's, if you arrive from elsewhere it's still pretty bad, because there are just too many people there, and now that they have a program to turn the landscape back into a desert, so the gardeners just blow dust around ....
 

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as an aside, perhaps the smog check would be far more effective if they quit checking for non-CARB approved intakes on closed loop fuel injection, and instead looked for cracking fuel lines, as one good car fire on the freeway not only burns all kindsastuff,
but also causes all the other vehicles to sit. for a long time. I don't think special CA blends of gas help much in that scenario, and I have no idea if they erode fuel lines faster.
 
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