View Poll Results: What Octane Do You Use
87
5
2.03%
89
10
4.07%
91
94
38.21%
Higher
137
55.69%
Voters: 246. You may not vote on this poll
What Octane Do You Use
Race Director
Joined: Apr 2007
Posts: 18,048
Likes: 53
From: long Island NY
Race Director
Joined: Mar 2007
Posts: 18,308
Likes: 21
From: Marlton. Increasing performance one speeding ticket at a time! NJ
All else equal, I run premium, though.
Last edited by nj02vette; Mar 11, 2008 at 08:45 PM.
Race Director
Joined: Aug 2003
Posts: 16,270
Likes: 30
From: "It's 106 miles to Chicago, we've got a full tank of gas, half a pack of cigarettes, it's dark, and
St. Jude Donor '03-'04-'05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16-'17-‘18-'19
NCM Sinkhole Donor
This is the reply from someone who knows.....
You can run 87 octane in YOUR cars - it's your privilege. I will run Premium unleaded Top Tier fuel in mine, because that's how Chevrolet engineered the car to run at it's best, and that's how my car runs best. I just wouldn't want to be the poor dumba$$ that buys the car used from you guys running 87 octane in them all the time.
Originally Posted by Evil-Twin
This is why I hate some of the posts here,,,,,
The manual says you can use a low octane fuel in a stuck situation.
( what this means is, in the event you need gas and the only station around is out of 91 octane, you can use it to get yo the next station)
the car is not meant to be driven on anything less than 91 octane.
Using less than 91 octane will cause a knock retard condition, reducing ignition timing, and poor performance. It will only cause engine damage over time... the difference between regular and 91 octane is 10 cents.
if you spend 30 dollars a week its 3 dollars, thats 150 dollars a year. if you cant afford that, then you should not buy a corvette. I am not being smart, just honest. Corvettes can be costly to maintain as well. If you are that worried about gas prices what are you going to do with a 75 dollar oil change,or if something goes wrong with the 7 computer modules found in a Corvette, they are all over 500 dollars . water pump is a 500 dollar fix...
a front wheel bearing replacement is 500 dollars... 4 tires are 800 to 1200 dollars.
I'm telling you this like you were my son or brother,.
Good luck
Bill aka ET
This is why I hate some of the posts here,,,,,
The manual says you can use a low octane fuel in a stuck situation.
( what this means is, in the event you need gas and the only station around is out of 91 octane, you can use it to get yo the next station)
the car is not meant to be driven on anything less than 91 octane.
Using less than 91 octane will cause a knock retard condition, reducing ignition timing, and poor performance. It will only cause engine damage over time... the difference between regular and 91 octane is 10 cents.
if you spend 30 dollars a week its 3 dollars, thats 150 dollars a year. if you cant afford that, then you should not buy a corvette. I am not being smart, just honest. Corvettes can be costly to maintain as well. If you are that worried about gas prices what are you going to do with a 75 dollar oil change,or if something goes wrong with the 7 computer modules found in a Corvette, they are all over 500 dollars . water pump is a 500 dollar fix...
a front wheel bearing replacement is 500 dollars... 4 tires are 800 to 1200 dollars.
I'm telling you this like you were my son or brother,.
Good luck
Bill aka ET
Last edited by blacksedan87; Mar 11, 2008 at 08:43 PM.
Le Mans Master
Joined: Jul 2005
Posts: 7,121
Likes: 3
From: Shreveport/Bossier Louisiana
St. Jude Donor '08
Unless you are seeing KR under a WOT load...it will feel no different.
If you can tune specifically for that fuel, and get some timing advance out of the deal, then perhaps....
Best performance without tune alteration = the lowest octane you can get away with without inducing knock/ping.
If you can tune specifically for that fuel, and get some timing advance out of the deal, then perhaps....
Best performance without tune alteration = the lowest octane you can get away with without inducing knock/ping.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Top 10 C9 Corvette MUST-HAVES to Fix These C8 Generation Flaws!
Michael S. Palmer
10 Revolutionary 'Corvette Firsts' Most People Don't Know
Joe Kucinski
5 Reasons to Upgrade to an LS6-Powered Corvette; 5 Reasons to Stay LT2
Michael S. Palmer
Race Director
Joined: Oct 2002
Posts: 16,477
Likes: 26
From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Anyone with tuning software knows.
E-T obviously had no part of the PCM programming logic.
Under normal operating conditions, the PCM uses two basic (fixed) timing tables...a high octane table, and a low octane table. It will normally reference the high octane table, and set timing as such, until the point knock is detected.
If a slight amount of knock is detected (long before audible), the PCM will set the timing somewhere in between the values of the high/low tables, and yes, it is always in a constant state of readjustment.
When knock is no longer detected, timing will be advanced again.
The only time the PCM will fully switch to the low octane table is if a MAF or knock sensor DTC has been set.
The use of 87 octane will NOT damage the engine over time, and won't even cause the PCM to run solely from the low octane timing table. It MIGHT cause the actual timing to be slightly retarded during operation, yes, affecting performance, , but never below the low octane table, which is still plenty safe for the engine.
E-T obviously had no part of the PCM programming logic.
Under normal operating conditions, the PCM uses two basic (fixed) timing tables...a high octane table, and a low octane table. It will normally reference the high octane table, and set timing as such, until the point knock is detected.
If a slight amount of knock is detected (long before audible), the PCM will set the timing somewhere in between the values of the high/low tables, and yes, it is always in a constant state of readjustment.
When knock is no longer detected, timing will be advanced again.
The only time the PCM will fully switch to the low octane table is if a MAF or knock sensor DTC has been set.
The use of 87 octane will NOT damage the engine over time, and won't even cause the PCM to run solely from the low octane timing table. It MIGHT cause the actual timing to be slightly retarded during operation, yes, affecting performance, , but never below the low octane table, which is still plenty safe for the engine.
Burning Brakes
Joined: Mar 2006
Posts: 750
Likes: 82
From: Bedford IN
Administrator
Joined: Mar 2001
Posts: 368,075
Likes: 24,732
From: In a parallel universe. Currently own 2014 Stingray Coupe.
C7 of the Year - Modified Finalist 2021
MO Events Coordinator
St. Jude Co-Organizer
St. Jude Donor '03 thru '25
NCM Sinkhole Donor
CI 5, 8 & 11 Veteran
Normally 91 octane, but have used 89 octane before with no knock or pinging noticable.
Team Owner
Joined: Mar 2007
Posts: 35,136
Likes: 2,097
From: Right Corner Pocket of Illinois
No-IL Events Coordinator
2026 Corvette of the Year Finalist - Unmodified
2025 C6 of the Year Winner - Unmodified
2020 C6 of the Year Finalist - Unmodified
2020 Corvette of the Year Finalist (appearance mods)
2019 C6 of Year Winner (appearance mods)
2018 C6 of Year Finalist
St. Jude Donor '12 thru '26
93 Shell V-Power in my V8! 
Thread Starter
Drifting
Joined: Jul 2006
Posts: 1,564
Likes: 4
From: Brookfield Wisconsin
I have been using Premium since I bought the car, my friend has had his Vette for years and said a GM tech told him he could run 87 in it cause the computer would compensate for the difference.
I only use Premium but wanted to know if this was true. Now I know it is true but cheap-o's are the only ones running the 87.
I only use Premium but wanted to know if this was true. Now I know it is true but cheap-o's are the only ones running the 87.
