Works out about the same out of pocket 
What octane do you guys use?
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
Not to get too windy about it, but let's all remember what octane is. It is not a power rating. You don't go faster or produce more horsepower because you use a higher Octane.
What does happen is, the octane rating tells you/gives you a number, below which your engine will knock. Knock is early detonation and that will ruin an engine, slowly or quickly.
Yes, your engine management system will compensate to a degree for lower octane gas (which is closer to the limit of permitting your engine to knock and some knock is inaudible....), but do you really want that?
Remember, we are the same people who agonize over:
1) Mobil One vs. Walmart synthetic oil
2) 160, 180, 195 degree thermostats and engine temps approaching 228
3) K&N oil filter vs. NAPA gold or Fram
4) AC Delco puck-dropping platinums vs. Bosch Plus 4 and NGK Iridiums,
etc., etc.
And we're going to worry about $0.20 cents per gallon of gas which prevents an engine from knocking and igniting compressed gasoline without a spark and thus doing damage to our engines?
Lemme put it this way: Do you really want to buy someone's used, higher-compression Corvette that's been run consistently on lower-octane gas?
What does happen is, the octane rating tells you/gives you a number, below which your engine will knock. Knock is early detonation and that will ruin an engine, slowly or quickly.
Yes, your engine management system will compensate to a degree for lower octane gas (which is closer to the limit of permitting your engine to knock and some knock is inaudible....), but do you really want that?
Remember, we are the same people who agonize over:
1) Mobil One vs. Walmart synthetic oil
2) 160, 180, 195 degree thermostats and engine temps approaching 228
3) K&N oil filter vs. NAPA gold or Fram
4) AC Delco puck-dropping platinums vs. Bosch Plus 4 and NGK Iridiums,
etc., etc.
And we're going to worry about $0.20 cents per gallon of gas which prevents an engine from knocking and igniting compressed gasoline without a spark and thus doing damage to our engines?
Lemme put it this way: Do you really want to buy someone's used, higher-compression Corvette that's been run consistently on lower-octane gas?
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
there's been a gazzilion discussions about this..specifically Octane ratings and how they burn, seems like we have some chemical engineers on the forum. Most disussions have ended with...burn the lowest octane you can without causing it to ping (knock).
Race Director
Joined: May 2005
Posts: 11,992
Likes: 1,331
From: Middletown, DE
Originally Posted by Barbara_S
I use what the owners manual says to use on every car I own and have owned.
Just because a motor can run on lower octane fuel doesn't mean it's going to perform it's best.
Just because a motor can run on lower octane fuel doesn't mean it's going to perform it's best.
For my '93 the performance difference was very noticable when I experimented with 87 octane. It didn't knock or anything, which is as it should be given the knock sensor. Just felt more sluggish. I could not compare gas mileage because my usage patterns are not consistent enough tank to tank.
The owner's manual calls for 91; premium at all the stations around here is 93 so that's what I use. I did not experiment with 89 midgrade -- the stuff is only 10 cents cheaper than the 93 so why bother?
Last edited by Rapid Fred; Aug 3, 2006 at 03:44 PM.
Team Owner
Joined: Feb 2006
Posts: 24,460
Likes: 7
From: sw Ohio
Originally Posted by Mr Mojo
First off, premium isn't that much more, maybe 20-25 cents a gallon more? So we're talking $5 a tankful. It's worth it to go a little longer.
On a road trip, I was getting close to 30 mpg using 93 octane where someone else on the same trip on the same roads in the same year car was only getting 21. After talking a while we discovered he was using 87 octane.
So calculate the difference in the $5 you save or 9 mpg more, which is better?
On a road trip, I was getting close to 30 mpg using 93 octane where someone else on the same trip on the same roads in the same year car was only getting 21. After talking a while we discovered he was using 87 octane.
So calculate the difference in the $5 you save or 9 mpg more, which is better?
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Burning Brakes
Joined: Jun 2005
Posts: 871
Likes: 2
From: Orlando Fl
Ive been told, by several mechanics, that the higher octane does my 86 L98 no more good than regular. That being said...
I just FEEL BETTER putting in higher octane gas, and it gets the higher octane (premium) probley 60-70% of the time. Its just a few dollars more, and my baby is worth it.
I just FEEL BETTER putting in higher octane gas, and it gets the higher octane (premium) probley 60-70% of the time. Its just a few dollars more, and my baby is worth it.
Melting Slicks
Joined: Feb 2005
Posts: 3,474
Likes: 44
From: Auburn MA
I use Exxon 93 primarilly because the gas station near my work runs a sale on premium on tues and thurs and it sells for the same price as middle grade (89) which last time i tanked up was 3.15/gal
Advanced
Joined: Jan 2006
Posts: 55
Likes: 0
From: Philadelphia Pennsylvania
I use 93 octane exclusively. It just isn't worth it for the difference it may cause in performance. We don't have 91 so to start mixing 87 or 89 with 93 would be a real PITA just to save a few pennies........
Racer
Joined: Jan 2005
Posts: 477
Likes: 21
From: Knoxville TN
Originally Posted by LT4CompYell
Whatever's premium, wherever I am with the car. 91 some places, 92 or 93 other places.
i sometimes for kicks and giggles put 110 in it from the gas station down the street...but at 5 something a gallon thats a rare occurance
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
"I use Exxon 93 primarilly because the gas station near my work runs a sale on premium on tues and thurs and it sells for the same price as middle grade (89) which last time i tanked up was 3.15/gal"
How do you know it's not the Middle Grade? Anyone ever test it?
How do you know it's not the Middle Grade? Anyone ever test it?
Team Owner
Joined: Sep 2002
Posts: 22,209
Likes: 12
From: OBAMA IS HITLER
Originally Posted by Gazpar
Ive been told, by several mechanics, that the higher octane does my 86 L98 no more good than regular. That being said...
I just FEEL BETTER putting in higher octane gas, and it gets the higher octane (premium) probley 60-70% of the time. Its just a few dollars more, and my baby is worth it.
I just FEEL BETTER putting in higher octane gas, and it gets the higher octane (premium) probley 60-70% of the time. Its just a few dollars more, and my baby is worth it.
additionally, over the long run, using unnecessarily high octane will cause excess unburnt fuel to trash up your cats.
bottom line: there is no practical reason to run octane thats any higher than recommended by the mfr.
oh, i always love the comment "nothing but the best for my baby", or similar, that cracks me up every time
i've got some snake oil by the case you'll be VERY interested in 
