At the pumps
Thread Starter
Instructor
Joined: Aug 2009
Posts: 137
Likes: 1
From: Easley SC
At the pumps
So its about time for me to fill up my Vette for the first time. I want to put premium gas into the tank like the manual tells you to. My dad wants to put in regular unleaded. Any suggestions on what to put into the tank?
Le Mans Master
Joined: Jan 2006
Posts: 6,564
Likes: 6
From: Woodstock Georgia
Right in the middle - mid grade for everyday driving. In fact I try to stay with Chevron since it has the Techron additive in it.
Congrats on the new vette, that is a heck of a smile on your face.
Congrats on the new vette, that is a heck of a smile on your face.
Drifting
Joined: Sep 2003
Posts: 1,363
Likes: 7
From: 1994 LT1 Coupe 6-speed with FX3 & 2000 LS1 Vert 6-Speed with F45 Hunterdon County, NJ
Please DO NOT listen to your dad, follow your gut and the manual's recomendations.
Remember when the engine was designed and the manual written, 'oxegenated' fuel wasn't typical, and Sunoco Ultra was 94 octane (at least in NJ). Now all fuels are lower octane too...
Also, premium fuel IS fuel which has been refined more than regular fuel, thereby it will have less contaminants and also wait for the spark plug to ignite it, rather than explode because its 'boiling point' is lower.
And, whereas the engine may not knock, it will be because the 'knock sensor' is causing the computer to retard the timing, negatively impacting performance and mileage.
Lastly, premium gas WILL give you better gas mileage -- so when you add it up over the year, there may not be any difference in overall cost, and in fact you may actually spend less using premium.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
don't listen to your dad. He will cheap out, and the minute you nail it, your engine will begin a fast deterioration.
Suddenly, your compression will fall off, and you will notice blowby, and less snapwhen you mash the go pedal.
The manual was written for intelligent people who can read and understand english.
Not someone who is getting close to the end of their earning cycle, and looking to save pennies while lavishly wasting dollars.
yes, yes, I know you love your dad..............
Suddenly, your compression will fall off, and you will notice blowby, and less snapwhen you mash the go pedal.
The manual was written for intelligent people who can read and understand english.
Not someone who is getting close to the end of their earning cycle, and looking to save pennies while lavishly wasting dollars.
yes, yes, I know you love your dad..............
Last edited by coupeguy2001; Sep 18, 2009 at 12:04 AM.
Drifting
Joined: Jun 2007
Posts: 1,261
Likes: 2
From: Prather, California -1990 ZR-1 White/Flame Red- -SOLD!!-
I always put premium in mine, but 91 is the highest you can get around here. Used to be 92 or 93 like 10 years ago, but for some reason its been downgraded.
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Burning Brakes
Joined: May 2009
Posts: 1,027
Likes: 1
From: Woodland CA
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
it's a corvette for cripes sake at least put premium in it. LOL even a c4 deserves it.
My dad runs low grade in his, says no problems. I have heard you can have a knock with junk gas.
93 or higher for me, I run 87 in my lawnmowers
My dad runs low grade in his, says no problems. I have heard you can have a knock with junk gas.
93 or higher for me, I run 87 in my lawnmowers
Then you just just have to buy more gas.
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
If you want to follow the "ME TOO" crowd, fill it with dollar bills. The "nothing is too good for my baby", group feels better when they throw money at their cars. Octane has one purpose, and one purpose only. It suppresses and/or prevents knock. If your mug is full of coffee, do you keep filling it, for "insurance"? Once the mug is full, you are done, for now. What spills, is unused and wasted, just like more octane than you can use. If your engine doesn't knock or the computer isn't pulling timing because the knock sensor is detecting and reporting knock counts, adding octane is useless and a waste of money. The best gasoline value for you and your car is the lowest octane that doesn't allow knock. Engines vary, as do driving styles, and environments. The best for your car, may not be the best for my, identical, car. If you will experiment, you can save yourself some money AND improve your performance. One way the higher octane gasoline suppresses knock, is to burn slower, reducing cylinder pressures. Just about every modification you do to your car to increase performance is designed to raise the cylinder pressure for more power. If you know what is what and how things work, the answer is obvious.
RACE ON!!!
RACE ON!!!
Burning Brakes
Joined: May 2009
Posts: 1,027
Likes: 1
From: Woodland CA
I'm not an expert with fuel, but according to my 1996 manual:
I live in Southern CA that has lots of hills. Since the manual is recommending the use of 91 octane, that is what I use unless the manual is incorrect.
Fuel
If you have the 5.7L Code5 engine, use premium
unleaded gasoline rated at 91 octane or higher.
If you have the 5.7L CodeP engine, use premium
unleaded gasoline rated at 91 octane or higher for best
performance. You may use middle grade or regular
unleaded gasolines, but your vehicle may not accelerate
as well.
At a minimum, the gasoline yous e should meet
specifications ASTM D4814 in the UniteSd tates and
CGSB 3.5-M93 in Canada. Improved gasoline
specifications have been developed btyh e American
Automobile Manufacturers Association (AAMA) for
better vehicle performance ande ngine protection.
Gasolines meeting the AAMA specificationco uld
provide improved driveability ande mission control
system protection comparedt o other gasolines.
Be sure the posted octanfeo r premium is at least 91
(at least 89 for middle grade and 87 for regular). If the
octane is less than 87, you may get a heavy knocking
noise when you drive. If it’s bad enough, it can damage
your engine.
If you’re using fuel rated at the recommended octane or
higher and you stillh ear heavy knocking, your engine
needs service. But don’t worry if you hear a little
pinging noise when you’re accelerating or driving up a
hill. That’s normal, and you don’t have to buy a higher
octane fuel to get rid of pinging, It’s the heavy, constant
knock that means you have a problem.
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood tune-up label),
it is designed to operate on fuels that meet California
specifications. If such fuels are not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp on
your instrument panel may turn on and/ory our vehicle
may fail a smog-check test. If this occurs, return to your
authorized Corvette dealer for diagnosis to determine
the cause of failure. In the event it is determined that the
cause of the condition is the type of fuels used, repairs
may not be covered by your warranty.
If you have the 5.7L Code5 engine, use premium
unleaded gasoline rated at 91 octane or higher.
If you have the 5.7L CodeP engine, use premium
unleaded gasoline rated at 91 octane or higher for best
performance. You may use middle grade or regular
unleaded gasolines, but your vehicle may not accelerate
as well.
At a minimum, the gasoline yous e should meet
specifications ASTM D4814 in the UniteSd tates and
CGSB 3.5-M93 in Canada. Improved gasoline
specifications have been developed btyh e American
Automobile Manufacturers Association (AAMA) for
better vehicle performance ande ngine protection.
Gasolines meeting the AAMA specificationco uld
provide improved driveability ande mission control
system protection comparedt o other gasolines.
Be sure the posted octanfeo r premium is at least 91
(at least 89 for middle grade and 87 for regular). If the
octane is less than 87, you may get a heavy knocking
noise when you drive. If it’s bad enough, it can damage
your engine.
If you’re using fuel rated at the recommended octane or
higher and you stillh ear heavy knocking, your engine
needs service. But don’t worry if you hear a little
pinging noise when you’re accelerating or driving up a
hill. That’s normal, and you don’t have to buy a higher
octane fuel to get rid of pinging, It’s the heavy, constant
knock that means you have a problem.
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood tune-up label),
it is designed to operate on fuels that meet California
specifications. If such fuels are not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp on
your instrument panel may turn on and/ory our vehicle
may fail a smog-check test. If this occurs, return to your
authorized Corvette dealer for diagnosis to determine
the cause of failure. In the event it is determined that the
cause of the condition is the type of fuels used, repairs
may not be covered by your warranty.
Last edited by Wathen1955; Sep 18, 2009 at 03:46 PM.
Pro
Joined: Mar 2008
Posts: 579
Likes: 2
From: High Bridge New Jersey
Use premium!
fer Chrissakes, the engineers that wrote the manual and designed the engine know a HECK of a lot more than me or you or your Dad! (no offense)
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
RACE ON!!!
Le Mans Master
Joined: Mar 2001
Posts: 7,999
Likes: 14
From: Life is just one big track event. Everything before and after is prep and warm-up and cool-down laps
Cruise-In III Veteran
Cruise-In IV Veteran
St. Jude Donor '12
What year is your car?
In my 88 I would use regular for "around town, and commutting" Would occasionaly get knock if I did not use a name brand fuel (Texaco, Chevron, etc.). When autocrossing and running on a road course - premium was in the tank with no knocking.
In my 92 I tried regular in one tank and it ran like crap. I ran a couple tanks of mid-grade for running around town and got OK mileage. I ran a couple tanks of premium for running around town and got a couple mpg better. Your mileage will vary, this is how my car runs.
With those experiments complete I'm running premium because my engine likes it better.
You should run the same type of experiment and see what yours likes. CFI-EFI is correct that all cars can run on regular - its just how well they run on it. I don't run premium because it says "premium reccomended", I run it because my car is happier.
Another data point, my wife has a 2004. She runs mid-grade almost exclusively, gets great gas mileage and now has 102K miles. It doesn't like regular very much, she has had to run it in the past and gas mileage suffered. We just got done with a 1800 mile trip and highway mileage was around 30 mpg.
In my 88 I would use regular for "around town, and commutting" Would occasionaly get knock if I did not use a name brand fuel (Texaco, Chevron, etc.). When autocrossing and running on a road course - premium was in the tank with no knocking.
In my 92 I tried regular in one tank and it ran like crap. I ran a couple tanks of mid-grade for running around town and got OK mileage. I ran a couple tanks of premium for running around town and got a couple mpg better. Your mileage will vary, this is how my car runs.
With those experiments complete I'm running premium because my engine likes it better.
You should run the same type of experiment and see what yours likes. CFI-EFI is correct that all cars can run on regular - its just how well they run on it. I don't run premium because it says "premium reccomended", I run it because my car is happier.
Another data point, my wife has a 2004. She runs mid-grade almost exclusively, gets great gas mileage and now has 102K miles. It doesn't like regular very much, she has had to run it in the past and gas mileage suffered. We just got done with a 1800 mile trip and highway mileage was around 30 mpg.
Team Owner
Joined: Sep 2003
Posts: 20,176
Likes: 673
From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
If you want to follow the "ME TOO" crowd, fill it with dollar bills. The "nothing is too good for my baby", group feels better when they throw money at their cars. Octane has one purpose, and one purpose only. It suppresses and/or prevents knock. The best for your car, may not be the best for my, identical, car. If you will experiment, you can save yourself some money AND improve your performance.
Recently I ran a test and bought nothing but Chevron premium for the first leg on our vacation. The second leg I filled with 87 octane. Same overall performance with less hurt to the wallet.
