V6 on 87 octane

[benji1997]

The differences in octane number originate in chemical mixtures created at the refinery, and different grades of gasoline are kept separate throughout the distribution process. The right grade to buy is the one your particular car was engineered for; you need to use only a grade high enough to prevent knock. ''Putting premium in a car designed to run on lower octane is a waste of money,'' said Dennis Simanaitis, the engineering editor of Road and Track magazine.
Using regular in a car designed for premium, however, is a mistake. ''If a car is rated to run on premium, it will still run on 87 or 89, but the engine computer will dial back its performance and you won't get optimum performance or gas mileage,'' Mr. Simanaitis said. In that kind of car, ''using premium fuel will eliminate the knock,'' he added, ''and the engine computer will deliver full performance.''
So which grade of gasoline is right for your car? Look in your owner's manual.

[TooCool5]

Originally Posted by benji1997

The differences in octane number originate in chemical mixtures created at the refinery, and different grades of gasoline are kept separate throughout the distribution process. The right grade to buy is the one your particular car was engineered for; you need to use only a grade high enough to prevent knock. ''Putting premium in a car designed to run on lower octane is a waste of money,'' said Dennis Simanaitis, the engineering editor of Road and Track magazine.
Using regular in a car designed for premium, however, is a mistake. ''If a car is rated to run on premium, it will still run on 87 or 89, but the engine computer will dial back its performance and you won't get optimum performance or gas mileage,'' Mr. Simanaitis said. In that kind of car, ''using premium fuel will eliminate the knock,'' he added, ''and the engine computer will deliver full performance.''
So which grade of gasoline is right for your car? Look in your owner's manual.

^^^ ^^^

[Waste]

I started out using 93 octane when I first bought my car, after a few months I tried 87 octane and noticed no difference and have continued using it. No knocking, no weird noises. To each his own though.. It's all perception it seems.

[Mvp_Me]

93 still burns more efficient though.

[AmericanMuscleCars]

93 octane isn't that much more expensive, sure i wont be saying that 6 months down the road but whatever...

[911medic]

Originally Posted by Mvp_Me

93 still burns more efficient though.

Explain, please. Are you referring to 93 octane in general, or specifically in our engines?

[Mvp_Me]

Originally Posted by 911medic

Explain, please. Are you referring to 93 octane in general, or specifically in our engines?

in general, even in this tank that i drive when i had 87 and i was late for work and i was doing "spirited driving" it was like i had water in the tank but running 93 the fuel is lasting longer with regular driving and "spirited driving" for me in some places 93 isn't much higher for now. when and if it skyrockets again ill go down to 91. 93 is not a must have but it burns more effectively thus leading to not visiting the pump so often. if gas quality didn't matter why do they make different grades of it? thats my question to you all.....
like stated above it a has been put on paper that the v6 pulls timing with hard pulls with 87 so yes you can use what ever gas grade you want but just know that if you are one to do spirited driving from time to time you wont be getting the most out of your motor BUT if you drive like the retired folks down in florida you could give two sh*ts about the gas you put in. its says you can put 87 in the car but do you have to???? no and we all kno that. everything gives us a choice if you look at it, down to meds, you can take one or two pills depending on strength; all little off topic but you get the point and that is use whats good for you.
i just hate it when people don't open there minds to see the facts, even if you want to use 87 at the end of the day don't act like 93 is a complete waste because its not.
if i ever used anything short of 93 in my cobalt i could kiss my block gooooodbye with one good pull at wide open throttle. and before you say 93 in a cobalt it was a s supercharged converted to turbo running 24psi stock block. once again this car is in a whole different class but i am just trying to open the minds from a different prospective.
lastly i am in no way telling people to use 93 on a daily basis im just want to point out that it is a better quality grade over 87......simple.

[SC2150]

The knock sensors on all modern engines will detect the detonation and pull timing before the human ear can hear it, so if you could audibly hear any you have deeper issues or the knock sensors could be desensitized in the tune, etc.

All I can say is we see it on the dyno all the time, and logging the cars while running.....and that is not imagined. And yes, any low compression engine designed for 87 it would be a waste to run 93 in....but these engines are not low compression.

[TooCool5]

Ultra lean burn or stratified charge mode is used for light-load running conditions, at constant or reducing road speeds, where no acceleration is required. The fuel is not injected at the intake stroke but rather at the latter stages of the compression stroke. The combustion takes place in a cavity on the piston's surface which has a toroidal or an ovoidal shape, and is placed either in the center (for central injector), or displaced to one side of the piston that is closer to the injector. The cavity creates the swirl effect so that the small amount of air-fuel mixture is optimally placed near the spark plug. This stratified charge is surrounded mostly by air and residual gases, which keeps the fuel and the flame away from the cylinder walls. Decreased combustion temperature allows for lowest emissions and heat losses and increases air quantity by reducing dilation, which delivers additional power. This technique enables the use of ultra-lean mixtures that would be impossible with carburetors or conventional fuel injection.[1] [2][3

[TastyBake]

Originally Posted by SC2150

The knock sensors on all modern engines will detect the detonation and pull timing before the human ear can hear it, so if you could audibly hear any you have deeper issues or the knock sensors could be desensitized in the tune, etc.

All I can say is we see it on the dyno all the time, and logging the cars while running.....and that is not imagined. And yes, any low compression engine designed for 87 it would be a waste to run 93 in....but these engines are not low compression.

Can anyone pull the dyno #s for 87 vs. 93? I would love to see them!

[knowitman]

Originally Posted by Mvp_Me

in general, even in this tank that i drive when i had 87 and i was late for work and i was doing "spirited driving" it was like i had water in the tank but running 93 the fuel is lasting longer with regular driving and "spirited driving" for me in some places 93 isn't much higher for now. when and if it skyrockets again ill go down to 91. 93 is not a must have but it burns more effectively thus leading to not visiting the pump so often. if gas quality didn't matter why do they make different grades of it? thats my question to you all.....
like stated above it a has been put on paper that the v6 pulls timing with hard pulls with 87 so yes you can use what ever gas grade you want but just know that if you are one to do spirited driving from time to time you wont be getting the most out of your motor BUT if you drive like the retired folks down in florida you could give two sh*ts about the gas you put in. its says you can put 87 in the car but do you have to???? no and we all kno that. everything gives us a choice if you look at it, down to meds, you can take one or two pills depending on strength; all little off topic but you get the point and that is use whats good for you.
i just hate it when people don't open there minds to see the facts, even if you want to use 87 at the end of the day don't act like 93 is a complete waste because its not.
if i ever used anything short of 93 in my cobalt i could kiss my block gooooodbye with one good pull at wide open throttle. and before you say 93 in a cobalt it was a s supercharged converted to turbo running 24psi stock block. once again this car is in a whole different class but i am just trying to open the minds from a different prospective.
lastly i am in no way telling people to use 93 on a daily basis im just want to point out that it is a better quality grade over 87......simple.

However it is not that simple. Different grades of fuel have nothing to do with the quality of fuel. It is purely a rating of how easily the fuel will detonate based on a laboratory analysis using various tests. Higher octane ratings simply mean that the gasoline and air mixture can be under more pressure and at a higher temperature before the mixture detonates. In fact, 93 octane gasoline has a lower energy content than 87 octane fuel.

Most cars on the road are designed for 87 octane fuel. This means that during normal operation of those vehicles, the temperature and pressure in the cylinder do not get hot enough for 87 octane fuel to detonate. Running 93 octane fuel will not give any benefit in these motors because 87 octane fuel is sufficient for optimal timing in the motor.

Most types of sports cars have higher compression motors. Running a higher compression ratio allows for a car to operate more efficiently on a thermodynamic basis. When comparing two engines that are identical in everything except for the compression ratio, the engine with the higher compression ratio will have more horsepower and fuel efficiency. However, this engine might require a higher octane fuel than the lower compression motor because a higher compression ratio creates more heat and pressure in the combustion chamber. Most cars are built around 87 octane because the increase in power isn't as important and the increase in efficiency isn't enough to justify requiring more expensive fuel.

Cars that have turbos or superchargers generally require higher octane fuels because the act of forcing more air in the combustion chamber means that more pressure and heat is generated during the compression stroke when compared to a naturally aspirated motor. This is also why most turbo or supercharged cars run low compression ratios. The ZL1's LSA engine has a 9.1:1 compression but still requires 91+ octane fuel because the supercharger compressing the air creates the extra heat and pressure.

While turbocharged and supercharged cars tend to require a higher octane rating for the compression ratio of their engine, Direct Injected cars, such as the V6 Camaro, can run a lower octane fuel for the same compression ratio. In a traditional motor, the air and fuel are mixed before the mixture enters the cylinder during the intake stroke. Thus, both the air and fuel and compressed during the compression stroke. As the mixture is compressed it also gets hotter and will eventually detonate. In a direct injection motor only the air enters the cylinder during the intake stroke. The fuel is then added during the compression stroke. This means that the fuel has less time to heat up during the compression stroke and is less likely to detonate. Adding the fuel during the compression stroke also has another benefit. When the fuel is injected into the hot combustion air it wants to evaporate. This latent heat of vaporization then cools both the fuel and air because the fuel is pulling heat out of the air in order to vaporize.

I'm trying to not debate whether or not higher octane fuel benefits the V6 motor in this post. I am just trying to state that octane rating is not a "quality" rating of fuel. It is just the quantification of a particular property of the fuel.

[MBS]

Originally Posted by knowitman

However it is not that simple. Different grades of fuel have nothing to do with the quality of fuel. It is purely a rating of how easily the fuel will detonate based on a laboratory analysis using various tests. Higher octane ratings simply mean that the gasoline and air mixture can be under more pressure and at a higher temperature before the mixture detonates. In fact, 93 octane gasoline has a lower energy content than 87 octane fuel.

Most cars on the road are designed for 87 octane fuel. This means that during normal operation of those vehicles, the temperature and pressure in the cylinder do not get hot enough for 87 octane fuel to detonate. Running 93 octane fuel will not give any benefit in these motors because 87 octane fuel is sufficient for optimal timing in the motor.

Most types of sports cars have higher compression motors. Running a higher compression ratio allows for a car to operate more efficiently on a thermodynamic basis. When comparing two engines that are identical in everything except for the compression ratio, the engine with the higher compression ratio will have more horsepower and fuel efficiency. However, this engine might require a higher octane fuel than the lower compression motor because a higher compression ratio creates more heat and pressure in the combustion chamber. Most cars are built around 87 octane because the increase in power isn't as important and the increase in efficiency isn't enough to justify requiring more expensive fuel.

Cars that have turbos or superchargers generally require higher octane fuels because the act of forcing more air in the combustion chamber means that more pressure and heat is generated during the compression stroke when compared to a naturally aspirated motor. This is also why most turbo or supercharged cars run low compression ratios. The ZL1's LSA engine has a 9.1:1 compression but still requires 91+ octane fuel because the supercharger compressing the air creates the extra heat and pressure.

While turbocharged and supercharged cars tend to require a higher octane rating for the compression ratio of their engine, Direct Injected cars, such as the V6 Camaro, can run a lower octane fuel for the same compression ratio. In a traditional motor, the air and fuel are mixed before the mixture enters the cylinder during the intake stroke. Thus, both the air and fuel and compressed during the compression stroke. As the mixture is compressed it also gets hotter and will eventually detonate. In a direct injection motor only the air enters the cylinder during the intake stroke. The fuel is then added during the compression stroke. This means that the fuel has less time to heat up during the compression stroke and is less likely to detonate. Adding the fuel during the compression stroke also has another benefit. When the fuel is injected into the hot combustion air it wants to evaporate. This latent heat of vaporization then cools both the fuel and air because the fuel is pulling heat out of the air in order to vaporize.

I'm trying to not debate whether or not higher octane fuel benefits the V6 motor in this post. I am just trying to state that octane rating is not a "quality" rating of fuel. It is just the quantification of a particular property of the fuel.

damn good post and thread , So I got to ask you since you own a Zl1 and have no bias in this I am assuming , If you owned a 2010 LT what gas would you use ? Say you wanted a little more acceleration ,,I always use top-teir 89 , they do not have 93 top tier ,but do have 91 ?

[Mvp_Me]

Originally Posted by knowitman

However it is not that simple. Different grades of fuel have nothing to do with the quality of fuel. It is purely a rating of how easily the fuel will detonate based on a laboratory analysis using various tests. Higher octane ratings simply mean that the gasoline and air mixture can be under more pressure and at a higher temperature before the mixture detonates. In fact, 93 octane gasoline has a lower energy content than 87 octane fuel.

Most cars on the road are designed for 87 octane fuel. This means that during normal operation of those vehicles, the temperature and pressure in the cylinder do not get hot enough for 87 octane fuel to detonate. Running 93 octane fuel will not give any benefit in these motors because 87 octane fuel is sufficient for optimal timing in the motor.

Most types of sports cars have higher compression motors. Running a higher compression ratio allows for a car to operate more efficiently on a thermodynamic basis. When comparing two engines that are identical in everything except for the compression ratio, the engine with the higher compression ratio will have more horsepower and fuel efficiency. However, this engine might require a higher octane fuel than the lower compression motor because a higher compression ratio creates more heat and pressure in the combustion chamber. Most cars are built around 87 octane because the increase in power isn't as important and the increase in efficiency isn't enough to justify requiring more expensive fuel.

Cars that have turbos or superchargers generally require higher octane fuels because the act of forcing more air in the combustion chamber means that more pressure and heat is generated during the compression stroke when compared to a naturally aspirated motor. This is also why most turbo or supercharged cars run low compression ratios. The ZL1's LSA engine has a 9.1:1 compression but still requires 91+ octane fuel because the supercharger compressing the air creates the extra heat and pressure.

While turbocharged and supercharged cars tend to require a higher octane rating for the compression ratio of their engine, Direct Injected cars, such as the V6 Camaro, can run a lower octane fuel for the same compression ratio. In a traditional motor, the air and fuel are mixed before the mixture enters the cylinder during the intake stroke. Thus, both the air and fuel and compressed during the compression stroke. As the mixture is compressed it also gets hotter and will eventually detonate. In a direct injection motor only the air enters the cylinder during the intake stroke. The fuel is then added during the compression stroke. This means that the fuel has less time to heat up during the compression stroke and is less likely to detonate. Adding the fuel during the compression stroke also has another benefit. When the fuel is injected into the hot combustion air it wants to evaporate. This latent heat of vaporization then cools both the fuel and air because the fuel is pulling heat out of the air in order to vaporize.

I'm trying to not debate whether or not higher octane fuel benefits the V6 motor in this post. I am just trying to state that octane rating is not a "quality" rating of fuel. It is just the quantification of a particular property of the fuel.

well said and cant argue with your statement, its what i wanted to say but i was lazy to explain it the way you did. maybe because you have a zl1 you might grab some of the peeps attention



honestly im really going to see if my buddy at his race shop can hook me up with two pulls. one with 87 and one with 93, both with a full tank. even if im wrong or not i just need to know for myself and if i do it ill record it.

[Jalberdi99]

Originally Posted by Jalberdi99

will put 93 today and report back in a few days

just filled up last week with a fresh full tank of 93, much smoother acceleration, and responsive