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Discussion Starter #1
Simple question, i am thinking of using some race gas that is around town? So far I have two choices here. 1)100 Octan and 2)110 unleaded. I know the obvious gains but what about the down falls if any? Like any o2 damage and/or plug life? Please info would be nice and some advise. T/Y in advance!
 

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Waste of money. Race gas wont make the bike run any better or create any more power. Run the lowest octane gas that does not cause the engine to ping/detonate. If anything, race gas will be more likely to foul spark plugs and leave deposits in the combustion chambers which could eventually lead to pinging/detonation if used over an extended period of time. These bike can drink and live off the low octane stuff just fine and be very happy with it.

Think 87 octane gas won't make power? See this thread --> http://www.kawiforums.com/forum/topic.asp?TOPIC_ID=70616
 

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Originally posted by xtremewlr
Waste of money. Race gas wont make the bike run any better or create any more power. Run the lowest octane gas that does not cause the engine to ping/detonate. If anything, race gas will be more likely to foul spark plugs and leave deposits in the combustion chambers which could eventually lead to pinging/detonation if used over an extended period of time. These bike can drink and live off the low octane stuff just fine and be very happy with it.

Think 87 octane gas won't make power? See this thread --> http://www.KawiForums.com/forum/topic.asp?TOPIC_ID=70616
+1 If anything you are losing power and fuel economy. Unless you have an engine that is modified to the point that it pings on lower octane fuels, there is no reason to use anything above the factory recommended fuel. Now if you want to spend a ton of money on getting a little bit of gain, you can always buy yourself some oxygenated race gas or similar stuff, but it won't be good for your engine and it certainly won't be cheap.
 

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The only plus to running race gas on a street bike that doesn't require that high of an octane level is the fact that 110 octane smells OH SO GOOD!!!!!!!!!!!!!!!!! That's all. :D
 

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run 91 octane unless you've changed the compression on your bike...search octane and read it up
 

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Originally posted by xtremewlr
Waste of money. Race gas wont make the bike run any better or create any more power. Run the lowest octane gas that does not cause the engine to ping/detonate. If anything, race gas will be more likely to foul spark plugs and leave deposits in the combustion chambers which could eventually lead to pinging/detonation if used over an extended period of time. These bike can drink and live off the low octane stuff just fine and be very happy with it.

Think 87 octane gas won't make power? See this thread --> http://www.KawiForums.com/forum/topic.asp?TOPIC_ID=70616
yup what he said.
 

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Discussion Starter #9
Thanks for info..... I will Agree with the smelling good part. I won't be buying the smeel good stuff anymore... Oh Some one said on here that if I had some work done like a pipe, heads, cams, Air-filter and power commander..... The smell good Gas would be the only reason.....

Thanks For the info.......

Biktober fest is here and man there are beautiful bikes here....
 

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read this and save yourself:

OCTANE stands for iso-octane, a standard fuel stock used for comparison against n-heptane, another standard fuel stock.
In 1928 the Cooperative Fuel Research Committee developed a detonation testing machine. Their single cylinder, valve-in-head, watercooled, 612cc test engine had variable compression. While running at 600 rpm, the engineers gradually increased compression until a knock indicator sensed detonation. The highest compression value that resists detonation is assigned a number. It is referred to as the Research Octane Number (RON).

Unfortunately, the 1912 test device was not accurate enough for modern engines. Or rather, the gasolines with high RON numbers weren't suitable for high-load, high-rpm use. So, a new test machine was devised. Similar in makeup to the RON unit, this one ran at 900 rpm, but incorporated variable ignition advance. With the new testing device, gasoline could be tested under a load that was similar to the severe, sustained high-speed and high-load conditions of modern engines.

The rating from this machine is called a Motor Octane Number (MON) and it is always lower than the RON.
The octane rating of a gasoline primarily controls the amount of heat the fuel can tolerate before a second flame front can get started. Some persons have described Octane Rating as the relative speed of combustion. In other words they believe octane governs how fast a fuel burns. That is incorrect. The speed of combustion, just superficially, may or may not decrease with higher octane in the standard methods of fuel testing in a research engine: Motor, Research, Aviation or Supercharged. The speed of combustion is more a factor of the ingredients of the fuel and the actual compression ratio in the engine being tested.
WHAT IS RON+MON/2?

RON+MON/2 is the anti-knock index number that is listed on the pump at your friendly local service station. It is derived by adding the RON figure to the MON and then dividing the sum by two. The difference between those two numbers indicates the fuel's sensitivity to detonation.

WHICH OCTANE NUMBER SHOULD I BELIEVE?

While the MON is the only octane count of any real value, gas stations don't post it. All you are given is the anti-knock index number. That could be misleading. A gas with a lower MON and a higher RON could have the same index number as a gas with a lower RON and a higher MON. The numbers don't always jive with the desired result. What you want is the highest possible MON, but the oil companies don't tell you that. The only way you can judge is by how your car runs.

If you are buying race gas, always ask for the Motor Octane Number (MON).

HOW MUCH OCTANE DOES PREMIUM UNLEADED HAVE?
That depends. In most states it's 92-octane. But, California has recently switched to 91-octane. In remote, low pollution areas, it's still possible to find 93-octane premium unleaded. If you live in Colorado (or at 10,000 feet) the best pump gas at the local station will only be 87-octane unleaded (engines require less octane at high elevations).


WILL MY CAR/BIKE RUN BETTER WITH MORE OCTANE?
No! Not if it runs correctly on pump gas. If an engine can be ridden under a race load without detonating-even with 91-octane unleaded premium-you seldom find hidden power in $6-a-gallon race gas. Octane alone doesn't dictate how much horsepower an engine makes-and more octane does not equate to more power (in fact, sometimes the equation runs the other way).

WHAT ARE OXYGENATES?
Oxygenates are chemicals that contain oxygen, have a good anti-knock value and reduce the smogforming tendencies of exhaust gases. Oxygenates replace most of the aromatics previously used to boost octane in unleaded fuels. The EPA mandates that oxygenated fuel be used in major metropolitan areas. Cities that lie in these areas are labeled "Reformulated Gas Cities." Some of these Reformulated Gas Cities are only required to sell oxygenated fuel during the summer or when air quality is at its worst. But some, like Los Angeles, pump oxygenated fuel year round.

Methyl tertiary butyl ether (MTBE) and ethanol are the two most common oxygenates. Ether is the active oxygenate in MTBE and corn alcohol is the active oxygenate in ethanol.
The downside of the oxygenate MTBE is that it might contaminate municipal water supplies. When ether mixes into water, it's very difficult to remove. Environmentalists want MTBE eliminated, but since the oil companies have yet to find a replacement oxygenate that has the same octane value as MTBE, the octane value of gasoline in high-density areas has lost an octane because of the reduction in MTBE.

WHAT ABOUT ETHANOL?
Ethanol is used in the corn growing states of the Midwest. The rest of the country gets MTBE because the oil companies only use ethanol where corn is readily available. The greatest expense in the gas business is the transportation and storage of gasoline. No one would pay the price ( in the works) to transport ethanol to California.

WHAT ARE THE PROBLEMS WITH ETHANOL?
Ethanol, like alcohol and brake fluid, is hydroscopic. That means it absorbs moisture. Since oil floats on water, there is a concern that moisture could cause the premix oil to separate in the gas. It's mostly a non-issue though, because ethanol is sold during the drier summer months. Plus, vigorous shaking before pouring, and agitation over whoops, doubles and triples keeps, the premix in a solution.

The quality of ethanol is also an issue. Each time ethanol is moved from one location to the next, it is opened and exposed to the atmosphere. If you get an old supply of ethanol, moisture contamination could have turned it into a cheap, lower octane gas. But, it will still be pumped into your gas can from a premium handle and at a premium price.

WHAT ARE WINTER AND SUMMER GAS?
Oil refineries alter the fuel mixture to accommodate the weather. The winter blend is formulated for easier starting in colder temperatures. Winter gas has been known to boil in the carb line and create enough vapor lock to keep the engine from running right.

In the summer, the gas mixture is reformulated for warmer climes and mostly to ease smog concerns. In the Reformulated Gas Cities, especially Los Angeles, gas stations sell summer gas year round.

ARE PUMP GASOLINES DIFFERENT?
You bet. Each oil company has their exclusive mix of octane enhancers, antioxidants, metal deactivators, deposit modifiers, surfactants, anti-icers, corrosion inhibitors and dyes.
It gets better yet. Just because you buy Chevron doesn't necessarily mean that what you're pumping was originally destined to be sold under a striped Chevron banner. If Hee-Haw Gas next door is going out of business, who knows where their underground supply of reduced-price gas will end up?

WHO SELLS THE BEST PUMP GAS?
You never know, but there are a few precautions you can take to increase your odds of getting good gas. (1) Buy fuel from a name-brand station. (2) Choose a station in a high-use area and one that sees frequent business. The more gasoline the station sells, the fresher the supply will be.

WHEN SHOULD I USE RACE GAS?
This is the $6-a-gallon question. There are five reasons you might need to run race gas: (1) If your engine has been modified with more ignition and compression, it will likely need more octane. (2) If you experience detonation with the best available premium unleaded. (3) If the consistency and quality of local pump fuel is questionable. (4) Some car/bike brands take to race gas better than others and, when re-mapped, re-jetted etc, mods , etc, produce more horsepower. (5) You're too cool and like to spend money.




ARE RACE GASES DIFFERENT?
Not all race gases are a smart buy. Pro Circuit sells $5.75-a-gallon, 108-octane VP C-12, but races with $11-a-gallon, 106-octane VP MR-2. Why? Although lower in octane, MR-2 has a higher energy value and can potentially make more horsepower in a carefully tuned race engine. Some of the factory teams use $15-a-gallon
MR-1, which has a higher energy value yet, but a lower octane of 95.

IS LEADED BETTER THAN UNLEADED?
As long as the octane is sufficient, motorcycle engines don't know the difference between leaded and unleaded gas. Lead is the easiest and most economical way to raise octane during the fuel formulization process. That is why the race gas you purchase will generally be of the leaded variety. Four-stroke engines designed before the advent of unleaded gasoline used lead to lubricate the valve seats. Most all cars run on UNLEADED NOW.

WHAT ABOUT OCTANE BOOSTERS?
Most octane boosters contain toluene. Like MTBE, any component that is strong enough to boost octane is harsh enough to harden seals and turn plastic gas tanks yellow. The quality of the end product is only as good as the gas you mix it with. Octane boosters are a Band-Aid fix for when race gas is not available (and the local supply of gasoline is questionable). The worse the gas, the more you will benefit from octane boosters.

HOW FRESH SHOULD MY GAS BE?
If you use a plastic container, choose one with a darker color. Dark cans block out UV light better than white ones. Keep the gas in the shade and at a consistent temperature. Avoid wild swings in temperature that could make the fuel susceptible to evaporation and condensation.
It's best to use gas as soon as it is mixed and to keep the freshest supply on hand. As soon as you pour the fuel, immediately seal both tank's gas caps. If you ride every week and consistently run fuel through the bike's tank as well as the gas can, there is little concern of fuel breakdown.

HOW SHOULD I STORE MY FUEL?
Steel gas cans are better than plastic. Don't store fuel in a plastic gas tank or plastic gas can for longer than three weeks. If stored for extended periods in a plastic can the gases will evaporate through the porous plastic. You end up with a denser fuel that will effect jetting. Two months is the limit for gas in a steel can.

<-----Bikes----->

DO FOUR-STROKES NEED MORE OCTANE?
Two-strokes stand to benefit more from higher octane fuel than four-strokes. The design of a two-stroke's pipe keeps more heat backed up against the cylinder and creates the potential for hot spots that could lead to detonation.

CAN MY STOCK BIKE BENEFIT FROM RACE GAS?
Compared to pump gas, the quality of race gas will always be closer to what it's claimed to be. Running race gas allows for the potential to jet leaner for more, crisper, cleaner-hitting power. But there are no absolutes here. The bike you are riding will run the best with the octane it is tuned to use. If you run race gas in an engine that's tuned for pump gas, it can actually hurt performance.

CAN I MIX RACE GAS WITH PUMP GAS?
Yes. Lots of riders do it to save money. But don't think of it as improving the quality of pump gas, it's more like diluting the quality of the race gas. It does work, though, and many riders run a 50-50 mix of 92-octane pump gas and 100-octane race gas. The main caveat still remains, however: if your engine doesn't need race gas, it probably doesn't need a half-half mix either. Unless you have an unusual octane requirement and are on a tight budget, it's best to run pure race gas or pure pump gas.


WHAT ABOUT AVGAS?
Aviation fuel is controlled by a different agency and follows a different octane scale. Additives for altitude and temperature are also included, some of which are not compatible with premix oil for example if you run it in your 2 smoker. Unless you're thinking of jumping the Snake River on a rocket bike, avoid avgas.
 

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Word of caution....if you run any thing under 93 octane, make sure you stay loyal to gas brands. It's true I run 87 in my bike but I won't get 87 gas from 7-11 (citco), or any shady looking roadside gas station. Just stick to the commercial vendors like sunoco, exxon, and BP. I had a bad experience with my car from some of the non commercial gas vendors...bad or dirty fuel
 

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Heh, I have had good experience with Citgo and bad experiences with BP and Sunoco. I think everybody is different in their preferences. Sheetz is good, but it hasn't taken over the world yet. Give it a few more months. :)
 

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Originally posted by dcbb6
Word of caution....if you run any thing under 93 octane, make sure you stay loyal to gas brands. It's true I run 87 in my bike but I won't get 87 gas from 7-11 (citco), or any shady looking roadside gas station. Just stick to the commercial vendors like sunoco, exxon, and BP. I had a bad experience with my car from some of the non commercial gas vendors...bad or dirty fuel
I've run whatever is cheapest or readily available at the time, always 89 octane, never had issues at all. This goes for my truck and bike although I run 87 in the truck because its too damn expensive to fill the tank in that thing with the better stuff. [xx(]
 

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Originally posted by xtremewlr



I've run whatever is cheapest or readily available at the time, always 89 octane, never had issues at all. This goes for my truck and bike although I run 87 in the truck because its too damn expensive to fill the tank in that thing with the better stuff. [xx(]
What kind of truck do you have that requires higher than 87 octane?

Also, you refer to the more expensive stuff as "better". It really isn't "better", it just has a slower rate of burn to prevent knocking.
 

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+1 on the octane stuff... I run 87. I noticed that Sheetz consistantly has the best gas in my area, I always go out of my way for it. Sometimes Sunoco has bad gas. I will never buy gas from the "UniMart" station (which is closet to me) again.
 

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Originally posted by JStutz2003



What kind of truck do you have that requires higher than 87 octane?

Also, you refer to the more expensive stuff as "better". It really isn't "better", it just has a slower rate of burn to prevent knocking.
I never said my truck "required" higher than 87 octane. And I am fully aware of higher octane gas burning at a slower rate to help prevent knocking and pinging, also known as detonation. Why do you think I posted this.

Run the lowest octane gas that does not cause the engine to ping/detonate. If anything, race gas will be more likely to foul spark plugs and leave deposits in the combustion chambers which could eventually lead to pinging/detonation if used over an extended period of time.
I refer to 89 octane as "better" gas because it is usually the more consistant quality gas at any given pump as compared to 87 octane.
 

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Originally posted by JStutz2003



Also, you refer to the more expensive stuff as "better". It really isn't "better", it just has a slower rate of burn to prevent knocking.


zxhunter's article above seems to disagree.

Some persons have described Octane Rating as the relative speed of combustion. In other words they believe octane governs how fast a fuel burns. That is incorrect. The speed of combustion, just superficially, may or may not decrease with higher octane in the standard methods of fuel testing in a research engine: Motor, Research, Aviation or Supercharged. The speed of combustion is more a factor of the ingredients of the fuel and the actual compression ratio in the engine being tested.
 

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If lower octane doesn't burn faster, then why would running it cause things like ignition ratarding and pre-ignition? The article answers this itself one sentence before your quote: The octane rating of a gasoline primarily controls the amount of heat the fuel can tolerate before a second flame front can get started. Read: Higher octane=takes longer to ignite.

And Xtremewly, what leads you to believe that 89 has more consistant quality than 87? Never heard that one before.
 

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Originally posted by JStutz2003
If lower octane doesn't burn faster, then why would running it cause things like ignition ratarding and pre-ignition? The article answers this itself one sentence before your quote: The octane rating of a gasoline primarily controls the amount of heat the fuel can tolerate before a second flame front can get started. Read: Higher octane=takes longer to ignite.

And Xtremewly, what leads you to believe that 89 has more consistant quality than 87? Never heard that one before.
I'm not saying I know the answer, just pointing out that you two were contradicting each other.

Maybe it's not that it takes longer to ignite with higher octane, it's just burns more uniformly and doesn't ignite until it's suppose to (from the spark). The actual rate at which it burns may not be associated, I don't know.

Now I'm not trying to pretend I'm an expert, just trying to understand this stuff myself. Feel free to tear my comments apart if I'm wrong but here is my take.

In an engine, things are supposed to be timed just right so that the cycle works efficiently. Generally, you want the combustion to happen when the piston reaches the apex of its motion, TDC. If the air/fuel mixture ignited on its own from the heat caused during compression (too low of an octane), then the force of the explosion would work against the piston on its upward motion, which is bad right? Now I realize that its sometimes advantageous to advance the timing for a "fast" engine because of the time it actually takes to burn. But you get my point, too low of an octane is bad.

So I think I understand why you shouldn't use low octane, but what are the reasons to not use too high of an octane, other than cost? I've read that it can cause your engine to run worse, but why? I'm not seeing the physics behind it. Is it because of the additives used to make the octane higher have a lower energy value or what? If it doesn't burn slower, what difference does it make?
 
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