Both GM 3100s I owned pinged on 87 but not 89. That's well worth the extra $1.60 per fill. YMMV.
Purpose of 89 Octane?
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JHZR2
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My saab will advance timing for 90. It says so on the filler flap.
All the premium by us is 93. Not sure why, but it appears that the 91 max octane rating many cars have is due to CA and others only providing 91 max.
Not sure if some cars will advance up to 93 vice 91 without a custom tune.
But anyway, since my car will advance up to 90 octane, I put 89 in, and just once in a blue moon put 93 in to keep the average around 90. I also use 89 for 2-stroke lawn equipment because it is requested in the manual.
Why do we have it? I suppose in reality it is unneeded. In the USVI, all the stations sell is 87 and 93, no midgrade. There likely is no need, and I'd rather see 87 and a (lower cost) 91. Keep things simple...
All the premium by us is 93. Not sure why, but it appears that the 91 max octane rating many cars have is due to CA and others only providing 91 max.
Not sure if some cars will advance up to 93 vice 91 without a custom tune.
But anyway, since my car will advance up to 90 octane, I put 89 in, and just once in a blue moon put 93 in to keep the average around 90. I also use 89 for 2-stroke lawn equipment because it is requested in the manual.
Why do we have it? I suppose in reality it is unneeded. In the USVI, all the stations sell is 87 and 93, no midgrade. There likely is no need, and I'd rather see 87 and a (lower cost) 91. Keep things simple...
Originally Posted By: genynnc
My 03 Ram w/ Hemi specifies 89 octane in the manual. (Although I use 87 with no reported probelms).
My 05 Hemi Dodge also called for 89 (and I ran 87 too...).
My 03 Ram w/ Hemi specifies 89 octane in the manual. (Although I use 87 with no reported probelms).
My 05 Hemi Dodge also called for 89 (and I ran 87 too...).
Originally Posted By: The Critic
Around here, pumps have dispensers for 87, 89 and 91 octane fuels.
I have seen cars specify either 87 or 91, never 89. So what's the purpose of 89?
The purpose is to let me run my modified 10.3 CR SBC 383 on cheaper gas.
Around here, pumps have dispensers for 87, 89 and 91 octane fuels.
I have seen cars specify either 87 or 91, never 89. So what's the purpose of 89?
The purpose is to let me run my modified 10.3 CR SBC 383 on cheaper gas.
I watched and at sunoco stations as the stations by me show the readout for high and low octane seperatly. The 87 and 93 don't blend, 89 and 91 both do. You could write down and compare the changes in the 2 readouts before and after to get a good idea of the blend. It is noticable between 89 and 91 the ratio differnce.
Originally Posted By: The Critic
Originally Posted By: tomcat27
in my humble opinion, I think its to squeeze some extra profit outa people who want something better than regular, but wont pay for premium.
It appears to me that 89 is simply a blend of regular and premium - I could be wrong - but on one of the pumps I used both counters incremented when pumping midgrade.
89 is blended at pump. I'm curious what the ratio of 87 to 91 is though, in order to make an 89 blend.
Originally Posted By: The Critic
Originally Posted By: tomcat27
in my humble opinion, I think its to squeeze some extra profit outa people who want something better than regular, but wont pay for premium.
It appears to me that 89 is simply a blend of regular and premium - I could be wrong - but on one of the pumps I used both counters incremented when pumping midgrade.
89 is blended at pump. I'm curious what the ratio of 87 to 91 is though, in order to make an 89 blend.
89 is there because they have 3 pumps!
I use it in my super car for hwy trips.
I use it in my super car for hwy trips.
Originally Posted By: Durango
If gas goes any higher in my area then maybe I may have to ... buy lower for my 08 Impala SS which requires 91 octane gas.
This seems odd to me. No matter what the price for 87, gas stations seem to follow the +10 system for pricing the 89 and 91. Maybe +12.
So when gas gets expensive, it's proportionally less of an extra expense to step up a grade.
If you're living hand-to-mouth, then it makes sense to cut every last cent possible. Otherwise, don't sweat it.
If gas goes any higher in my area then maybe I may have to ... buy lower for my 08 Impala SS which requires 91 octane gas.
This seems odd to me. No matter what the price for 87, gas stations seem to follow the +10 system for pricing the 89 and 91. Maybe +12.
So when gas gets expensive, it's proportionally less of an extra expense to step up a grade.
If you're living hand-to-mouth, then it makes sense to cut every last cent possible. Otherwise, don't sweat it.
Originally Posted By: purelux
I watched and at sunoco stations as the stations by me show the readout for high and low octane seperatly. The 87 and 93 don't blend, 89 and 91 both do. You could write down and compare the changes in the 2 readouts before and after to get a good idea of the blend. It is noticable between 89 and 91 the ratio differnce.
Would you happen to know what that ratio is? We don't have Sunocos around here, or any gas station that employs a similar system.
Thanks.
I watched and at sunoco stations as the stations by me show the readout for high and low octane seperatly. The 87 and 93 don't blend, 89 and 91 both do. You could write down and compare the changes in the 2 readouts before and after to get a good idea of the blend. It is noticable between 89 and 91 the ratio differnce.
Would you happen to know what that ratio is? We don't have Sunocos around here, or any gas station that employs a similar system.
Thanks.
Originally Posted By: The Critic
Around here, pumps have dispensers for 87, 89 and 91 octane fuels.
I have seen cars specify either 87 or 91, never 89. So what's the purpose of 89?
Ethanol.
In some states like Illinois you'll find ethanol added to all gasoline. Ethanol has 87, 89, 91 (or 92) at their pumps. All have ethanol in them. To achive 87 ethanol blend they have to start with a lower octane fuel to hit the 87 octane target since adding ethanol raises the octane.
In states like Iowa, ethanol is not mandatory. You'll see it in 89 and 91/92 fuels. The 89 fuel is basically the exact same fuel as the 87 octane just with 10% ethanol added. I suspect its a cost saving measure for distribution purposes.
I've never seen 89 octane blended "at the pump" around here. A tanker shows up with and pumps into one of three tanks (87,89,91).
It sure isn't some kind of marketing tactic despite the pumps being labled regular (87), super (89), and premium (91) because 89 is always cheaper by 10 cents or better.
Around here, pumps have dispensers for 87, 89 and 91 octane fuels.
I have seen cars specify either 87 or 91, never 89. So what's the purpose of 89?
Ethanol.
In some states like Illinois you'll find ethanol added to all gasoline. Ethanol has 87, 89, 91 (or 92) at their pumps. All have ethanol in them. To achive 87 ethanol blend they have to start with a lower octane fuel to hit the 87 octane target since adding ethanol raises the octane.
In states like Iowa, ethanol is not mandatory. You'll see it in 89 and 91/92 fuels. The 89 fuel is basically the exact same fuel as the 87 octane just with 10% ethanol added. I suspect its a cost saving measure for distribution purposes.
I've never seen 89 octane blended "at the pump" around here. A tanker shows up with and pumps into one of three tanks (87,89,91).
It sure isn't some kind of marketing tactic despite the pumps being labled regular (87), super (89), and premium (91) because 89 is always cheaper by 10 cents or better.
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I always use 89 for lawn & garden and for marine use.
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