difference between 87 octane and higher
Safety Car
Joined: Sep 2006
Posts: 4,566
Likes: 6
From: Land of 10,000 taxes
While we're discussing dumb questions regarding octane...
Earlier, before the $3/gal. stuff, premium was always .20 mor per gallon than 87 octane regular. I've noticed that lately the spread in cost has increased. Is it actually costing more to refine premium grade gasoline than it used to? Why the spread to begin with?
Earlier, before the $3/gal. stuff, premium was always .20 mor per gallon than 87 octane regular. I've noticed that lately the spread in cost has increased. Is it actually costing more to refine premium grade gasoline than it used to? Why the spread to begin with?
Safety Car
Joined: Nov 2006
Posts: 3,860
Likes: 5
From: Tampa FL
Also, you're saving less than 22 cents per gal since your miles per gal will drop due to the timing being off.
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,015
Likes: 1
From: Deerfield beach Fl
I wish it was like that around here, 22 cents is like the low end, I"ve seen some places that are 30 cents or more spread for premium.
Le Mans Master
Joined: Jun 2002
Posts: 6,430
Likes: 3,620
From: Commerce Texas
Safety Car
Joined: Sep 2006
Posts: 4,566
Likes: 6
From: Land of 10,000 taxes
another option is to look around for midgrade, 89 octane, the place by me that sells premium for 10 cents more than regular sells midgrade for 3 cents more, a station diagonal from them only sells 89 octane for the same price as regular, they both are usually the cheapest places in town.
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Melting Slicks
Joined: Oct 2006
Posts: 2,228
Likes: 5
From: Gainesville Georgia
Since you've been using 87 for a while, you probably will not hear the knocking/pinging. Your Knock sensors and ECU has already taken care of that. Your ECU should have already learned it by now and your car should already be running on the 87 timing map. You can always switch back to 91 or higher anytime you want, your ECU will figure it out.
But then again I remembered test driving a used 2002 Z06 and under full throttle the car detonated like crazy. We pulled over and I put about 5 gallons of 91 octane and instantly the knocking went away. A knocking is a loud Klick Klick Klick sound under a full throtle, some ears will hear it some wont. Me, I can hear it instantly while some of my friends would look at me weird and ask "what sound"?
But then again I remembered test driving a used 2002 Z06 and under full throttle the car detonated like crazy. We pulled over and I put about 5 gallons of 91 octane and instantly the knocking went away. A knocking is a loud Klick Klick Klick sound under a full throtle, some ears will hear it some wont. Me, I can hear it instantly while some of my friends would look at me weird and ask "what sound"?
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,015
Likes: 1
From: Deerfield beach Fl
At least 10 cents difference here. I used to run 93 or 94 exclusively but switched to regular when prices shot up. Believe it or not, 300 dollars a year is a lot to some people. That goes towards my insurance or other daily living expenses. Thats how I manage to own this great car and hang out with you guys. 
another option is to look around for midgrade, 89 octane, the place by me that sells premium for 10 cents more than regular sells midgrade for 3 cents more, a station diagonal from them only sells 89 octane for the same price as regular, they both are usually the cheapest places in town.
Instructor
Joined: May 2007
Posts: 148
Likes: 0
From: Franklinville New Jersey
{[20000 miles/year]/[20 miles/gallon]} X $0.22/gallon = $220/year
$18.50/month for gas doesn't seem like a lot when you are driving a $45,000 + sports car.
Also seems a little strange that on the same board where we are worried about the difference between regular gasoline and "high octane" we have guys who intentionally go out and "melt down" tires that run $350/ea.
$18.50/month for gas doesn't seem like a lot when you are driving a $45,000 + sports car.
Also seems a little strange that on the same board where we are worried about the difference between regular gasoline and "high octane" we have guys who intentionally go out and "melt down" tires that run $350/ea.
Instructor
Joined: May 2007
Posts: 148
Likes: 0
From: Franklinville New Jersey
Sorry, but this is bad information. Gasoline octane is "blended" at the refinery to be and sold to whoesalers as 87, 89, 91, 93, etc. Refineries have units that convert lower octane belndstocks to higher octane blendstocks. This generally results in a volume shrinkage and partially explains the higher cost of increasing octane. Alkylation units (HF and Sulfuric) and Nahtha Reforming units are both examples of lower octane to higher octane conversion
Advanced
Joined: Dec 2006
Posts: 75
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From: Atlanta Georgia
Race Director
Joined: Mar 2007
Posts: 11,331
Likes: 18
From: Missouri City Texas
Is an extra 4 bucks going to kill you at the pump to use premium? You're driving a 50K dollar car, lol.
Edit-damn...should've finished reading the posts before I posted, lol.
Edit-damn...should've finished reading the posts before I posted, lol.
Last edited by FloydSummerOf68; Sep 5, 2007 at 08:48 AM.
Race Director
Joined: Mar 2007
Posts: 11,331
Likes: 18
From: Missouri City Texas
Thread Starter
Melting Slicks
Joined: Mar 2003
Posts: 2,015
Likes: 1
From: Deerfield beach Fl
I used to melt down tires as well, but not when they are expensive like on this car. I have yet to spin the tires. Just not worth it. And 220 is still money. Actually its more in my case because 20000 miles or so is just driving to work. I still actually drive the car for pleasure as well. I got my car getting squirrly on me in the morning so I can assure you guys its not losing that much power running 87.
Besides, the question of this thread was what is the main difference between 87 and 93. I don't understand why these threads always have to turn into a war.
Besides, the question of this thread was what is the main difference between 87 and 93. I don't understand why these threads always have to turn into a war.
{[20000 miles/year]/[20 miles/gallon]} X $0.22/gallon = $220/year
$18.50/month for gas doesn't seem like a lot when you are driving a $45,000 + sports car.
Also seems a little strange that on the same board where we are worried about the difference between regular gasoline and "high octane" we have guys who intentionally go out and "melt down" tires that run $350/ea.
$18.50/month for gas doesn't seem like a lot when you are driving a $45,000 + sports car.
Also seems a little strange that on the same board where we are worried about the difference between regular gasoline and "high octane" we have guys who intentionally go out and "melt down" tires that run $350/ea.
Race Director
Joined: Mar 2007
Posts: 11,331
Likes: 18
From: Missouri City Texas
Bottom line is this...if you're happy with regular, go ahead, but your car WILL run better, perform better, and get better milage with 93 over 87...the cleaning additives put into most premium gasses at high tiered stations will also help to keep your valves and injectors clean.
Melting Slicks
Joined: Nov 2006
Posts: 2,297
Likes: 12
From: Wheaton IL
I don't think people are trying to start an argument with you, I think they are pointing out a different way to look at things. If you really want to factor everything into the equation, maybe you should consider the resale value hit you face with 20k miles per year. It sounds like you enjoy driving your vette and if you want to put in 87, that is certainly up to you. Most vette owners are on the picky side, so they have a different mindset at the pump. I personally wouldn't ever consider putting anything less than 92 octane in my car, but I only put on about 3k miles per year and like the added power and that detergents included in higher octane premium fuels.
Melting Slicks
Joined: Oct 2006
Posts: 2,228
Likes: 5
From: Gainesville Georgia
The cost difference is so little, I have to laugh when people won't buy a car that takes 91 or better. At my gas station the difference between 87 & 93 oct is only .20 cents/gal. So If you have a big 20 gal tank thats a whopping $4.00! I don't know about you, but that seems like a great deal for better overall performance. 
* Sorry, I just read the post's above. This was already metioned, but it's so true. If you drive a Vette, I don't think 4-5 bucks are gonna put you in the poor house, unless you live in your Vette lol
* Sorry, I just read the post's above. This was already metioned, but it's so true. If you drive a Vette, I don't think 4-5 bucks are gonna put you in the poor house, unless you live in your Vette lol
Last edited by Vetteoholic; Sep 5, 2007 at 11:34 AM.
