Gas!
Melting Slicks
Joined: Mar 2001
Posts: 2,978
Likes: 280
From: Tulsa OK
I have been running 93 octane since my car was new. However, most of the gas stations here in Tulsa dropped 93 octane recently. After talking to the guys at Texas Speed, who did my heads/cam/header setup, they told me I should be okay on 91 octane. My compression is about 10.75 with my heads. I ran a full tank of 91 octane and turned the stereo off and paid close attention to the engine. Even in 100 degree temps and WOT runs, I didn't get any pinging. I have since found a couple of nearby gas stations that still carry 93 octane. I'll keep running 93 octane as long as I can get it, but I at least have the confidence that the car will run fine on 91 octane.
Safety Car
Joined: Jul 2005
Posts: 4,743
Likes: 0
From: Omaha Nebraska
St. Jude Donor '06
Like the first guy said in his post... are you worried about the extra cash outlay for Premium?? if you put 17 gallons in your tank at $.20 more a gallon for Premium, it's a max of $3.40 additional money over 89 Octane...
You're driving a Vette, not a Volkswagon or an old Dodge Dart... If you fill it once a week for a year it's only an extra $176.80... How much did you spend on mods this year?? Or beer?
You're driving a Vette, not a Volkswagon or an old Dodge Dart... If you fill it once a week for a year it's only an extra $176.80... How much did you spend on mods this year?? Or beer?
Instructor
Joined: May 2005
Posts: 170
Likes: 0
From: Oklahoma
Originally Posted by chocoholic
Unless this is a trick question, the answer is "the lowest octane rating that doesn't cause knock"
Using a higher octane rating than you need is just plain silly because, despite what people would like to believe, higher octane fuels do not produce more power and, in fact, may cause worse performance in and of themselves.
You'll hear all manner of rationalisations for the emotional case of using the most expensive; it's only a few pennies, it's a 50K sports car, my baby deserves the "good stuff" versus the "bad stuff", but the real answer lies in understanding how an internal combustion engine works and what an octane rating is all about.
Using a higher octane rating than you need is just plain silly because, despite what people would like to believe, higher octane fuels do not produce more power and, in fact, may cause worse performance in and of themselves.
You'll hear all manner of rationalisations for the emotional case of using the most expensive; it's only a few pennies, it's a 50K sports car, my baby deserves the "good stuff" versus the "bad stuff", but the real answer lies in understanding how an internal combustion engine works and what an octane rating is all about.
That is exactly why it reduces knock and allows you to run more boost/ compression. It is less explosive and resists pre-ignition. You make more power not because of the fuel itself but the advantage of being able to run a cyllinder with more pressure ( oxygen) and the side effect of more heat not causing your fuel to explode before the spark tells it to. If yur not knocking or " pre igniting" then you are robbing your car of potential power. Make sense?
I blend my gas for 93 to 95 using 101 and 91. We don't have 93 here locally. My car runs 11.3:1 compression and is tuned to 93 octaine by MTI. No reason for me to run higher becasue it did not knock. I run a little higher durring very hot months as added insurance secondary to my high cr.
Instructor
Joined: May 2005
Posts: 170
Likes: 0
From: Oklahoma
Originally Posted by mikes99corvette
103 or better here!
Nice car! With your mods and FI I would definatly run 101 plus. On my Single turbo Supra I would run 101 unleaded and keep the boost around 14 to 20 depending on what type of racing I was doing.
My Current NA car in my sig made 538 RWHP on 93 w/o detonation. Fully heat soaked road racing I would not take the chance so I will be running the full 101 unleaded when that time comes. For street driving, the 95 blend does great with out knock.
Love your wheels also
