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Hey all. I have an easy question. I want to know if my 1986 Fleetwood Brougham requires premium gas, or can I get by using regular (87 octane)?
 

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you have the Olds 307.... the manual says you *could* use regular, but as the 307 gets higher in miles it needs premium....and for the price differnce, I would use premium anyway......
 

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You can try regular and see how it runs. That's what it says to use in the 1990 owners manual I have. I think I saw that somewhere for my 1991 aswell.
 

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The chemistry of gasoline says you should use the lowest octane possible w/o running into detonation. The higher the octane, the slower the gasoline burns in the combustion chamber. It's also harder to ignite higher octane fuel.

So if you don't get any detonation with 87, go with it. You'll be wasting money with premium.
 

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My 1987 Brougham had a bit of detination on the bottom end. Even though my owners manual says that 87 should be fine I switched to 89/90 and the problem disapeared. If you're having problems with the 87, switch to a higher grade until the problem is gone.
 

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[QUOTE=davesdeville]That's 8.5:1 compression so it doesn't require premium. I don't really think premium's worth the extra money, but it's your choice.[/QUOTE]

"You'll be wasting money with premium"

It is not clean where they clean up, it's clean were they don't litter.

I use premium Chevron/Exxon on my car because of my philosphy on things.

Just an opinion
 
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I use 87 octane in my 87 Fleetwood w/crappy 307 (for now) and it runs fine. Its still slow as hell but no pinging or anything. :bouncy:
 

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Chevron said:
(http://www.chevron.com/prodserv/fuels/gas_qanda/api_octane.shtml)
In most vehicles no benefit is gained from using gasoline that has a higher octane number than is needed to prevent knock. However, in some vehicles equipped with a knock sensor (an electronic device installed in many modern engines that allows the engine management system to detect and reduce knock), a higher octane gasoline may improve performance slightly.
So premium is a waste with a low compression engine like this 307.

Lev, you're a weird one..
 

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i try running 87 in my 86 and it pings like crazy i agree completly that high octane is a waste in these cars ,i am thinking about retarding the timing a cople of degrees to compensate the 87 octane i never step hard on the pedal anyway whats the use :histeric:
 

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I generaly use premium in my vehicles, but that's just how
the experiments have turned out. It's cost me less per mile
in gas costs alone. This was true of my '90 Ranger, '94 Sable,
'97 Kia Sephia (don't laugh, that little car would hold a stable
130mph . . . okay, go ahead and laugh), '78 Monte Carlo,
and every motorcycle. The only one that it hasn't been true
of is my '77 SDV. The SDV just didn't care one way or the
other.

Find out your milage on regular when running for a month, then
do the same on premium. Compare your results with how it
runs with either gas.

-Dirk R.
 

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Mogul345 said:
The chemistry of gasoline says you should use the lowest octane possible w/o running into detonation. The higher the octane, the slower the gasoline burns in the combustion chamber. It's also harder to ignite higher octane fuel.

So if you don't get any detonation with 87, go with it. You'll be wasting money with premium.
ee
 

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I emailed GM about this question regarding 99 STS here was their reply

Sent GMCanada an email asking about gas, oil, options this is the reply

Mr. Kozlowski:

Thank you for your e-mail.

In response to your questions regarding your 1999 Cadillac STS, and as outlined in the owner's manual, we wish to offer the following feedback:

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.

A "CHECK OIL LEVEL" message will appear when the engine oil is approximately one quart (1L) low. If you believe there may be an oil consumption concern, we can only recommend that you contact the service department of your local General Motors dealership for further assistance and investigation.

The Oil Life Indicator lets you know when to change the engine oil. It is based on the engine oil temperatures and your driving patterns.

We are unable to provide you with a service history on your vehicle. We recommend that you contact the selling party of the vehicle for this type of information.

Complete information regarding vehicle options and operations is available in the owner's manual. If this information was not included when you purchased the vehicle, you may order a manual through our distributor, Helm Incorporated. Please contact Helm directly, toll-free, at 1-800-782-4356, for further assistance and information.

We trust this information is of assistance to you, and we thank you for contacting General Motors of Canada Limited. Please visit our website again!


Heather Cameron-Johnston
Internet Correspondent
www.gmcanada.com
 

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I'm mandated by manufacurers requirements to use premium fuel in mine. Only in short term emergency am I permitted to use 89 octane. I've subjected to only one emergency. Now I understand the premium fuel requirement.
 

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I run a mix of 89 to 94 it mainly is 93 but it varies just like the wallet does, i tried 87 and my car got pissed at me.
 

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if i were u all....stop trying to save 10 cents extra on the gallon.....u own a caddy...not some cheap stupid car....u all say use rugular...how many have tested both? i ran 87 one time in my caddy 92 bro....just for 1 month strate to see the difference...didnt get better millage...actually got less....anddd the dam thing had barely any power...after that i went right back to 93 octane and the bad boy has some serious haulin power that should be coming for a 5.0 caddy! ....even with my old 87 bro...i used to put super all the time and tested out 87 oct...and it sucked......everyone just please try 93 oct for just one month...and see the difference...its night and day and sure does help u out in the long run. ;-)
 

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93 AND NOTHING BUT 93(OR94). MORE DETERGENTS IN 93 FOR A CLEANER FUEL SYSTEM.
I HAVE USED 93 IN EVERY V-8 I HAVE EVER OWNED.
FORGET ABOUT GAS MILEAGE. FOR A FEW CENTS MORE YOU GET A BETTER FUEL ...AND A BIT BETTER GAS MILEAGE. :cool:
 
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