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There is NO reason to use anything other than 87.

89 or above only helps if your engine is pinging/knocking etc.
If that's the case, bring it back to the dealer and have him fix it.

Kevin
 

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My C5 Corvette will run all day at any speed on 87 octane ( even though the owners manual states 90+)due to the computer controlled engine. Our SUV engines are also computer controlled, designed to run on 87 octane so anything higher is simply wasting money.
 

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All the above are correct. All my Vettes have run on 87 ...... except when I went to the track....then I needed all the power available so I put in 93. Even my Harley recommends 93, but has never seen anything above 87, but then again it's a stock engine.

I was told once that if your manual says "recommends" premium...you can use lesser grades OK
If your manual says "requires" premium.....you shouldn't use less then 93.
 

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If the engine detects pinging it will advance the timing so it drops the power. You don't know unless you hook a OBDII reader and check the pinging counter, if you have some then the fuel in your area is crap and probably you need to up to 89 or 91.
If there is no pinging then yes it is a waste...

Now that basically all fuels have some ethanol I don't know if the pinging problem is more than before.. (does ethanol cause more pre-detonation?)
 

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It's my understanding that ethanol does cause more pre-detonation. And, you tend to get more at lower grades. If you notice the sticker on most gas pumps say "up-to 10% ethanol" The higher octanes tend to be less ethanol. I don't have a solid source on that info though.

I've notice slightly better gas milage on higher octane, so it's not that much of a waste IMHO.
 

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oracle said:
If the engine detects pinging it will advance the timing so it drops the power.
FYI :

To reduce pinging, you need to retard the timing - NOT advance it.

And yes, this will reduce power.

(spoken from a person who used to own cars that you had control over the timing by rotating the "distributor" - a what, you ask - never mind, ask your father or grandfather !)
 

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OH-OH, I remember, I remember. ;D
My favorite was GM cars that had the slide door on the distrubutor to set the dwell. Tune ups were so easy.

I miss getting greasy and dirty working on my cars. At least I can still change the oil.
 

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You're right. I hope the guy that invented that "door" got a huge bonus. It made life so easy. I still have my dwell/tach, but I have no use for it. Maybe you'd like to "buy" it for a museum.
 

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Me too!

Gone are the times when you changed your timing belt or a suspension.

Now you cannot change your batery anymore! Just the oil change remains, who knows for how long... :(
 

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RIR333, I also still have mine and a remote starter button so I didn't have to get behind the wheel to start it.

AHHHHHH, the good old days. ;D

John, I can still change my batterys........after removing dozens of brackets, wires and hoses......... and the passenger seat. LOL
 

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GARYD said:
John, I can still change my batterys........after removing dozens of brackets, wires and hoses......... and the passenger seat. LOL
Yes, you still can, but after you change it you find out that everything is messed up because you reset the computer that controls everything. (PS. Don't blame the computer, i gain my daily bread with it ;))
 

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Yes, thanks for the correction. When I typed it something didn't look right.
And yes, I also used to rotate the distributor back in the days.. ;)

RIT333 said:
FYI :

To reduce pinging, you need to retard the timing - NOT advance it.

And yes, this will reduce power.

(spoken from a person who used to own cars that you had control over the timing by rotating the "distributor" - a what, you ask - never mind, ask your father or grandfather !)
 

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I guess I'll have to get that thing that you plug into the cigarette lighter to keep the computer going.
 
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