87 octane vs. 89 octane

[BriGy86]

There is a gas station near my work that sells 87 and 89 at the same price. The owners manual on my car says to use 87. Would I hurt my car by using 89 instead? And would I gain any more power, gas millage, etc?

 

[Bitek]

Its fine, prob not, nope

Just beware if its crap gas

 

[TheGizmo]

dont mix gas, always follow manufacture reccomendations for fuel

 

[Gibson486]

same price for both? how?

 

[BD2003]

You would gain absolutely nothing by using the 89.

Octane doesnt make gas better, it just prevents it from detonating, which is only an issue if you have a high compression engine. And if you do, your manual, and probably even the gas cap/door, will tell you so.

That being said, it won't hurt anything, but theres really no point, so don't bother.

 

[BriGy86]

Originally posted by: Gibson486
same price for both? how?

It is located on an Indian reservation, I think it may have to do with taxes.

I suppose I'll stick with 87 then.

 

[moomoo40moo]

Originally posted by: Gibson486
same price for both? how?

our kwik trip regularly has unleaded and unleaded plus at the same price. I usually put in the 89 octane, but I think I'm gonna start putting in 87 (recommended)

 

[BriGy86]

Originally posted by: BD2003
You would gain absolutely nothing by using the 89.

Octane doesnt make gas better, it just prevents it from detonating, which is only an issue if you have a high compression engine. And if you do, your manual, and probably even the gas cap/door, will tell you so.

That being said, it won't hurt anything, but theres really no point, so don't bother.

so higher performance cars user higher octane because they use higher compression?

 

[ScottFern]

Shell 87 octane for me!

 

[Christobevii3]

It isn't directly related to higher compression, a lower compression engine with a larger duration on the cam can cause the fuel to compress more than it would stock. Basically, use what you need, no reason for more.

 

[WhoBeDaPlaya]

Isn't the 89 octane stuff adulterated with alcohol? If that's the case, 87 would give better mileage.

 

[BD2003]

Originally posted by: BriGy86

Originally posted by: BD2003
You would gain absolutely nothing by using the 89.

Octane doesnt make gas better, it just prevents it from detonating, which is only an issue if you have a high compression engine. And if you do, your manual, and probably even the gas cap/door, will tell you so.

That being said, it won't hurt anything, but theres really no point, so don't bother.

so higher performance cars user higher octane because they use higher compression?

Its a vast oversimplification but its a large part of it. Gas companies call the 93 octane "premium" because it sounds better and helps them sell it...using higher octane in a car that runs on regular 87 isnt going to hurt anything, so they figure they might as well. Ignore the name "premium", it isnt better, it's just a different mix tuned for a different type of engine. My car requires premium...if I put 87 octane in it, it runs noticibly rougher.

 

[R Nilla]

In Iowa, 89 is usually cheaper than 87, because our 89 contains ethanol.

 

[OrganizedChaos]

with higher octane comes a higher driveability index.

why would you want to subject your vehicle to a higher DI?

 

[PricklyPete]

Originally posted by: BriGy86
There is a gas station near my work that sells 87 and 89 at the same price. The owners manual on my car says to use 87. Would I hurt my car by using 89 instead? And would I gain any more power, gas millage, etc?

If your car takes 87...no need for 89.

Some cars were designed around the stability Premium (91+) provides (often times forced induction engines). Some cars have on board computers that can adjust spark plug firing based on quality of gas...these will benefit some from 89 or 91+. In both cases, the cars manual would have said "Premium Only" or "Premium Recommended". Since your car manual just says 87...that's all you need. You will not get any benefit from 89.

 

[IsDanReally]

Also, like someone previously has said, higher octane gas get worse mileage in cars that don't require it. Definitely something to keep in mind.

 

[RU482]

Originally posted by: R Nilla
In Iowa, 89 is usually cheaper than 87, because our 89 contains ethanol.

You ever notice that the price per mile you drive is less for 87?

 

[fallensight]

Going higher wont hurt anything, usually the 89 is an ethonol blend. Keep in mind if you have never used ethonol and fill up on a tank of it, you have very good odds of clogging your fuel filter, especially if it is an older car with alot of miles with the cheap stuff.

 

[WhoBeDaPlaya]

Originally posted by: redly1
You ever notice that the price per mile you drive is less for 87?

That's what I said 😛
The dip in MPG for my isn't worth the slight discount over 87 octane. Besides, I frequent a station in the downtown area that always has crazily low pricing on 87 🙂

 

[AgentJean]

Does your car have a Oxygen Sensor? If it does, it really does not matter what grade gas you put in. The car will adjust the fuel to air mixture to get the best burn.

Putting 89 or even 93 Octane won't harm your car. You'll just be wasting money.
I put in Shell's highgrade every now and then to clean out the system from all the crap wawa and Sam's Club gas I put in but on every fill up(two expensive)

Some cares require higher grade gas because the engines use a slighly higher compression ratio and the higher pressure causes premature explosions with lowgrade gas. Something you'll never have to worry about driving a 4 cylinder.

 

[0roo0roo]

more octane = less energy
unless you have high compression engine as said, it is a total waste of money. more money for the terrorists!