V6 on 87 octane

[Mvp_Me]

93 is so much $$ over here
i used 93 in my SS cobalt but the tank was small, unlike the camaro; shes one thirsty beast.

[jameslk55]

My fiancee switched from 93 to 87 on her V6. We both could not feel any difference.

[Mvp_Me]

I will say this, i usually use 91 but this week i wasn't having it and tried 87 so when i look at the gas gauge it'll make me feel better inside. for regular driving its ok, you couldn't tell what gas was in it. i was almost late for work sunday and my gas went to nothing in no time because i was in a rush, i felt like i was driving a big turbo car with over 400whp the way the gas was burning and also the car felt sluggish at wot.
what im trying to say in a nutshell is that for me when im driving like a normal person the 87 works fine but try and pass someone or flooring it in general you will notice the difference. im no noob to this and i know without question 93 is best but it will cost you more mula and if you drive like a madman it will cost you even more but you get the most out of the 3.6L, imo mid-grade or 93 would be best but obviously 93 is best hands down. if it makes a difference the only mod i have is a airaid cai.

[markas214]

Originally Posted by Frank in MD

Not on a V6. V6 was designed to run regular unleaded gas. Premium on the 6'er is pointless.

Ran my RS for 2 1/2 years on 87. It ran great. The SS L99 must have 91 or higher as it affects the ECM. No need for anything above 87 with the V6. Mine would get up and go with no problem. Don't waste your money. Get a cold air intake if you want to see real improvement.

[ponywars]

87 works fine and youre driving a v6, if you wanna shell out extra money for performance why not get a v8

makes no sense, and 1-2mpg highway isnt gonna net you any savings with what you're paying for 91/93 instead of 87

[Mvp_Me]

Originally Posted by markas214

Ran my RS for 2 1/2 years on 87. It ran great. The SS L99 must have 91 or higher as it affects the ECM. No need for anything above 87 with the V6. Mine would get up and go with no problem. Don't waste your money. Get a cold air intake if you want to see real improvement.

Not to pick on you but i would say that you're wrong. just the fact that its a v6 doesn't mean use 87 because the rest have no benefit, it depends on the type of driver you are and what modz you have. its almost like saying just because its a 4cyl just use 87. my four banger had 388whp and the only gas i could use was 93 and the user manual said 93 is recommended and this is from factory so it all comes down to how you drive and how often you like to visit the pump (87 burns faster then 93)
this is not just towards you but all of the anti mid-grade and 93 ppl out there, and please don't get me wrong because i have 1/2 tank of 87 in my car now but its not a regular thing. i usually use mid-grade myself but ill use 93 next time around. Ive only had my car for four weeks now so this will be the first time ill be putting 93 in.

[Mvp_Me]

Originally Posted by ponywars

87 works fine and youre driving a v6, if you wanna shell out extra money for performance why not get a v8

makes no sense, and 1-2mpg highway isnt gonna net you any savings with what you're paying for 91/93 instead of 87

engine size doesn't mean a thing.....

[Travis64]

Originally Posted by GretchenGotGrowl

Do you have some evidence that is counter to the evidence many of have seen on the dyno and street logging the timing?

just try it,its easy to tell its a lot faster

[jrisebo]

Originally Posted by ponywars

87 works fine and youre driving a v6, if you wanna shell out extra money for performance why not get a v8

makes no sense, and 1-2mpg highway isnt gonna net you any savings with what you're paying for 91/93 instead of 87

Im not trying to claim better perfomance, MPG, etc. It just seems my car runs a bit smoother and a little more peppy....I still think the V6 is a great engine....blend of performance and economy.

If I was buying a Sunday driver....It would not be a Camaro.

[PoorMansCamaro]

http://www.camaro5.com/forums/showpo...6&postcount=59

[KaBoom1701]

I always go back and forth on this...

Some weeks I put only 87 in for the eco value, other weeks I put 91/93 in just to clean out the injectors and run some good gas through the car. Not sure on the performance edge by running higher octane. I look at it this way, I'm sure there is a small gain somewhere in our LFX engine with higher octane, just not sure how much?

[GretchenGotGrowl]

Originally Posted by bluebeastsrt

I don't have a nickel in it either way being that I'm tuned for 93 but would like to see a V6 dyno using both fuels.

Too lazy to do the search, but yes there is a thread where they showed it with a dyno. There's also a link in a post a few below yours that shows the amount of KR with 87 octane.

[SC2150]

We have done countless dyno's with our product development and show it every time. A search should show some as well that have been posted. With the VMax TB the results are even more dramatic.

It is not the size of the engine, it has nothing to do with it...it is the compression ratio.

On a L99/LS3/LS7/etc. if you run 87 the PCM switches timing tables to the low octaine tables and the performance/economy suffers as well. It is marketing that dictates the fuel as the V6 is considered the "entry level/economy" version of the camaro/caddy CTS, etc. Same with the cheap oil. Why in the world would a lower grade oil be reccomended in an engine that is far more susceptable to wear and damage due to the timing chains/tensioners when using a premium full synthetic eliminates the issues? The LLT with the Bosch ECU is constantly adjusting timing based upon spark knock (detonation) it reads. If no knock, then it runs full advance where the engine performs at its best both power and economy. The LFX with the GM PCM has the high and low octaine table not unlike the V8's so it will default to the low octaine and stay there unless reset or so many cycles of no detonation triggers it to high ocatine tables.

Any tuner can tell you, or show you in real time this happening on any engine.

Here is some reading on compression ratios and octane matching. Remeber, the LS3/L99 is 10.9:1 and the LLT & LFX are 11.3:1 Now if the engine was a 9.2:1 or 9.5:1 range, anything higher than 87 is a pure waste of $$....but this is not the case with these engines:


Compression Ratio and Detonation

For those who either never learned it or have forgotten, it's useful to know: Cars' internal combustion engines all function pretty much the same way. The vast majority of cars have four-stroke gas engines; each stroke, or compression stroke, is when a cylinder full of gas and air is compressed into a dramatically smaller volume before it is ignited with a spark plug [source: Arman].
To be more specific, a piston compresses the fuel and air mix in the combustion chamber of the engine. And the so-called compression ratio -- and each engine has its own ratio -- refers to just how much of that fuel and air combination the piston compresses. "In a four cylinder, 2-liter engine, each cylinder would have a 500 cc capacity," says John Nielsen, director of approved auto repair with the American Automobile Association (AAA). "As the piston moves down the cylinder, it draws in 500 cc of air and fuel. The valves close and the piston moves up, compressing the 500 cc charge. If that charge is compressed into 50 cc, the compression ratio of the engine would be 10:1."
Remember, under normal circumstances the compressed air and gas mix is ignited by a spark plug. But when that does not happen, and instead the mixture explodes in the combustion chamber rather than being ignited by the spark plug, that is called detonation -- or, as it is more commonly known, knocking and pinging [source: Nielsen].
To illustrate what is happening here, Nielsen says to think of a bicycle. In order to generate the most power, the optimum approach is to apply downward pressure at the top of the stroke and apply an even amount of pressure to just about the bottom of the stroke. "The same is true of a piston moving in the cylinder," he says. "When a cylinder detonates, the fuel burns at supersonic speed and releases its energy too fast, kind of like a fast stomp on the bicycle pedal."
Which brings us to the octane ratings in gasoline. Quite simply, octane ratings are a measurement of a gas's ability to resist detonation. Most gas stations offer three grades of octane, with regular rated typically at 87, mid-grade at 89 and premium at 92 or 93 [source: Federal Trade Commission]. It's easy to find what octane rating a gas has: Stations are required to post them on bright yellow stickers on each pump.

<LI class="font7 marginVertical3 pagelink"><LI class=" font7 marginVertical3 fadedText">Page <LI class="font7 marginVertical3 pagelink">1Compression Ratio and Octane Ratings: What You Need to Know

<LI class="font7 marginVertical3 pagelink">2Compression Ratio and Detonation

<LI class="font7 marginVertical3 pagelink">3Compression Ratio and Knock Sensors

<LI class="font7 marginVertical3 pagelink">4So what do you need to know?

<LI class="font7 marginVertical3 pagelink">Compression Ratio and Knock Sensors

If we all had to calculate what our car's compression ratio is, well, plenty of us would be in big trouble. That's because the formula is so long and has so many variables that even those who are proficient in math would never dare to consider it [source: Nielsen]. Fortunately, most owners' manuals have the compression ratio already calculated, and there's really no reason to know it or understand how it's derived. "Drivers don't ever have to calculate this. Mechanics usually don't, either," says Mike Arman, who has written numerous technical manuals on airplane and motorcycle engines. "People who modify engines must calculate this to determine -- which usually means guess -- the octane ratings of the fuel required."
Sometimes, a car's knocking and pinging is audible to the driver. But in other cases you'll never even hear a thing because a knock sensor has already corrected the problem. According to Arman, knock sensors are so-called piezo-electric microphones bolted to the engine block. "The knock detector talks to the ECU [the car's computer], which retards the timing to stop the knock," he says.






So what do you need to know?

Here's the good news: You don't have to know anything about the functioning of your engine to make sure you're putting fuel with the right octane rating in your tank. All you have to do is look into your trusty owners' manual and see what you should be doing. If your vehicle requires a high octane rating, the manual will tell you. Otherwise, don't pay the extra 15 to 20 cents per gallon for a higher octane fuel. "Putting high-octane fuel into a car that only needs low-octane fuel is a total waste of money," says Arman.
According to AAA's Nielsen, using a higher-octane fuel than your car requires won't hurt anything, but it also won't help -- and you'll be paying more for it, so it hurts in a different way. Then again, if your car is making knocking and pinging noises, it can be a good move to try a gas with a higher octane rating.
"Go up one grade of fuel and see if it solves the problem," says Arman. "It usually does." While occasional knocking and pinging is fairly normal and doesn't necessarily indicate any serious problem, persistent detonation-caused noise should not be ignored because it may lead to more serious engine damage.
Keep reading for more information on car engines and fuel economy.

KEEP in mind these engines are 11.3:1 CR!! Read ahead for more info and worksheets on calculating and determining the difference using 91-93 makes on your personal car:

FUEL OCTANE SELECTION



GOAL: To assist students in becoming wiser consumers of gasoline and enable them to select the proper octaned gasoline resulting in an energy savings as well as a monetary savings.
OBJECTIVES: Students will:
1. Realize that proper fuel octane selection can change MPG.
2. Recognize the economic benefit from proper fuel octane selection.
3. Understand that it takes more raw crude to refine higher octane fuels.
LESSON/INFORMATION: Fuel octane requirements for gasoline engines vary with the compression ratio of the engine; diesel cetane requirements also vary with the compression ratio. Engine compression ratio is the relative volume of a cylinder from the bottom most position of the piston's stroke to the top most position of the piston's stroke. The higher an engine's compression ratio, the greater the amount of heat generated in the cylinder during the compression stroke.
Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude.
If fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites too early and the fuel charge EXPLODES rather than BURNS resulting in incomplete combustion. The net effect is a loss in power and possible engine damage. The operator hears an audible "knock" or "ping", referred to as detonation. Detonation may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. Improper timing adjustments, vacuum leaks, or excessively lean fuel mixtures may also cause detonation.
Many vehicle owners believe that higher octane fuels are better for their vehicles since they are labeled "PREMIUM." The logic is that since it is a premium fuel it must be better. In reality, the premium label originates from the higher cost to refine and the resultant higher retail cost. Some refiners label their high octane fuels "SUPER." Some owners think that these fuels will make their vehicles more powerful. Only engines with high compression ratios can deliver all the potential energy from higher octane fuels! Always consult the manufacturer's octane recommendation to determine the proper octane requirements for any given vehicle. Generally, engines with compression ratios of 9.3 : 1 or less will safely operate with unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels.
Many owners who operate vehicles designed to operate on 87 octane fuel experience ping and knock. They usually "fix" this problem by purchasing the higher priced, higher octane fuels. Most owner's manuals indicate that some light and intermittent ping is normal but that heavy or sustained ping or knock should be attended to by either purchasing the correct octane fuel or servicing the engine.
Most fuel refiners blend fuels for geographic areas and adjust their blends seasonally. These blending techniques compensate for the decrease in oxygen content with an increase in altitude and compensate for volatility during the warmer or cooler seasons. Significant ambient temperature changes (40 degrees Fahrenheit) or altitude changes (4,000 feet) may cause some serious engine detonation. This problem is usually corrected by filling the tank with "local" fuel that has been properly blended for season and altitude.
ACTIVITY: 1. From the owner's manual, determine the octane requirements for a personal or family vehicle. If the owner's manual is not available, telephone, write or visit a franchised dealer for that vehicle to determine the appropriate octane fuel for that vehicle.
2. Make sure that the tank level is at ¼ or less before beginning this activity. Perform the "MPG test as outlined in the "Fuel Mileage Calculation" guide with the highest octane (91+ octane) fuel available for two sequential tanks. Calculate the two tank MPG. On the work sheet, note any extraordinary engine noises or performance problems during this test and note the cost per gallon.
3. Repeat step "2" for the next lower octane fuel (89 octane). On the work sheet, note any extraordinary engine noises or performance problems during this test and note cost per gallon.
4. If applicable, repeat step "2" a third time with lowest grade fuel (87 octane). On the work sheet, note any extraordinary engine noises or performance problems during this test and note cost per gallon.
5. For each grade of fuel, use the MPG and cost per gallon to project the fuel cost to operate this vehicle for 10,000 miles.
CULMINATING ACTIVITY: 1. Prepare a short report highlighting the need to determine octane for the selected vehicle.
2. Using your MPG data for each grade of fuel, compare the operating costs for ten years at 10,000 miles per year. Assume fuel costs $1.25 for 87 octane, $1.45 for 89 octane, and $1.65 for 91+ octane.
FUEL OCTANE WORK SHEET 1. Octane recommendation (source: owner's manual): _______
2. Fill tank with 91+ octane fuel; odometer reading: ______
3. Fill tank with 91+ octane fuel; odometer reading: ______
Gallons purchased: ______
Traffic Mix: ________________________
4. Fill tank with 89 octane fuel; odometer reading: ______
Gallons purchased: ______
Traffic Mix: ________________________
5. Fill tank with 89 octane fuel; odometer reading: ______
Gallons purchased:______
Cost per gallon: ______
Traffic Mix:________________________
6. Fill tank with 87 octane fuel; odometer reading: ______
Gallons purchased: ______
Cost per gallon: ______
Traffic Mix: ________________________
7. Fill tank with 87 octane fuel; odometer reading: ______
Gallons purchased:______
Cost per gallon:______
Traffic Mix:________________________
8. Type FuelCost/gallonMPGCost for 10,000 miles91+ octane


89 octane


87 octane



INFORMATION CHECK Place a "T" before the statements that are true and an "F" before the statements that are false. After each false statement, explain why it is false.
_______1. 91 octane fuel has more potential power than 87 octane fuel.
_______2. To release all the potential power of 91 octane gasoline, it is necessary for an engine to have a compression ratio higher than 9.3 : 1.
_______3. Any gasoline engine will efficiently burn any octane fuel.
_______4. The engine's compression ratio is the most important factor in selecting gasoline octane.
_______5. Posted fuel octane ratings are a result of testing fuel in the laboratory and under actual operating conditions.
_______6. Diesel engines require a low octane fuel.
_______7. Engine knock or ping is always a result of poor quality fuel.
_______8. Gasolines are seasonally and regionally blended.
TEACHER'S NOTES This is an important energy saving activity for students. Over the years, our society has somehow gotten the misnoma that a "Premium" grade fuel is better for a vehicle than a "Regular" grade fuel. Most vehicle owners never refer to their Owner's Manual to determine the acceptable octane fuel for their vehicle. Additionally, when a vehicle begins to knock and ping under acceleration, many owners apply a "quick fix" by switching to premium grade fuel. It is true that excessive and continued pinging and knocking is harmful to an engine and this MUST be attended to immediately or serious engine damage will result. Very few recently manufactured vehicles require premium, high octane fuel. To operate these vehicles with lower than required octane fuel could lead to immediate and serious internal engine damage. Most engines that do ping or knock on light acceleration do not need premium fuel; these engines need proper servicing such as timing adjustments, repairing vacuum leaks, or servicing emissions control valves. To operate a properly tuned engine designed for 87 octane with 89 or 91 octane fuel will only increase the cost of operation. No additional power, fuel economy, or durability will result from the higher octaned fuel.
ANSWERS TO INFORMATION CHECK: 3. False. To efficiently burn any fuel of any octane, the compression ratio of the engine must be high enough to release all the potential fuel energy.
6. False. Diesel engine fuels are rated in cetane numbers, not in octane numbers.
7. False. Engine knock or ping may be a result of too low an octane rating for that engine's compression ratio; most engine knocking and pinging is a result of an out-of-tune engine or emissions control servicing.
RECOMMENDED READING: Ellinger, Herbert E. Automechanics, Fourth Edition. Prentice Hall, Englewood Cliffs, New Jersey. 1988.
_____ United States Department of Energy. Energy Conservation Information for Vehicle Owners. U.S. Government Printing Office: 1991-289-606.
Shell Oil Company. How to Get More Miles Per Gallon. The Better Mileage Book. 1991.

[Mvp_Me]

Fu%k my life! Lol thread closed......