Is 89 octane gas obsolete?

[Wolf359]

Originally Posted By: motor_oil_madman
We have 89 here in Houston. Never seen a pump that didn't have anything but 87, 89 and 93. I do believe the 87 and 93 blend together to make 89 though, which is actually 90.


As previously stated, it's just a 1/3 mix of super to 2/3 regular to get 89 if you have 87 and 93. For those that need super, most cars only require 91 instead of 93 so you could do 2/3 super to 1/3 regular to get 91 instead of paying for 93. On the west coast they just have 91 because they have more cars that need super than on the east coast. If you do the math, it's always cheaper to make your own mix rather than use the 89 mix at the pump, but then you have to make two transactions.

And in terms of BTU per gallon, it's about the same so if your car is running right, if it calls for regular, you shouldn't see any improvement with plus or super, you're just wasting money and giving it to the oil companies because they've convinced you that you're treating your car by giving it plus or super.

 

[SHOZ]

Originally Posted By: Vern_in_IL
Surprised 89 is still around. All stations really need is 87 and 91/93.

Surprised the pumps didn't get converted over to E-85 or electric charge port by now.
Around me the Casey's are dropping the 89 oct for diesel.

 

[HTSS_TR]

How many vehicles recommend 89 the last 10 years ? Of the hundreds brands/models only a handful at most.

Costco stations in So Cal don't have 89 as long as I remember.

 

[Gasbuggy]

Originally Posted By: skyactiv
Easy answer. The gas pump at the station blends the highest octane with the lowest octane to create 89 octane.
Some auto makers have stated we don't get the same compression ratio and/or engine tune like the Europeans due to North Americas addiction to 87 octane.
In Europe. the Mazda Skyactiv 2.0L engine has 1 point higher compression and some VW/Audi and other vehicles can run a special lean burn due to peoples inability to pump an equivilent 87 octane swill in their tank.



Every station I'm aware of in the U.S. uses independent tanks for their 3 grades, you can count the caps in the parking lot. I've always thought 89 was a ripoff because I could blend 87 and 93 for the same price, usually less, at any given gas station.

I worked at a garage/gas station when I was a kid, we sold a surprising amount of 89. Almost as much as we sold high test. It gets two kind of buyers, the guy who should run 87 but likes to treat his car to a high grade, and the person who should run 91 but is cheap.

 

[steveh]

Originally Posted By: Wolf359
Originally Posted By: motor_oil_madman
We have 89 here in Houston. Never seen a pump that didn't have anything but 87, 89 and 93. I do believe the 87 and 93 blend together to make 89 though, which is actually 90.


As previously stated, it's just a 1/3 mix of super to 2/3 regular to get 89 if you have 87 and 93. For those that need super, most cars only require 91 instead of 93 so you could do 2/3 super to 1/3 regular to get 91 instead of paying for 93. On the west coast they just have 91 because they have more cars that need super than on the east coast. If you do the math, it's always cheaper to make your own mix rather than use the 89 mix at the pump, but then you have to make two transactions.

And in terms of BTU per gallon, it's about the same so if your car is running right, if it calls for regular, you shouldn't see any improvement with plus or super, you're just wasting money and giving it to the oil companies because they've convinced you that you're treating your car by giving it plus or super.
In my area its $1.95 for 87, $2.12 for 89, and $2.69 for 91.

 

[Rhymingmechanic]

Originally Posted By: HosteenJorje
89 E-10 is common at many Nebraska locations. I use SHELL 91 unleaded since the bottom fell out of crude oil. Probably go back to 89 E-10 when crude costs go back up.


It's like this at some Eastern Colorado locations, too. Pure gas for 87 and 91, and E10 for 89. In the past at least, the 89 "gasohol" was cheaper than 87 regular.

 

[fdcg27]

Originally Posted By: Rhymingmechanic
Originally Posted By: HosteenJorje
89 E-10 is common at many Nebraska locations. I use SHELL 91 unleaded since the bottom fell out of crude oil. Probably go back to 89 E-10 when crude costs go back up.


It's like this at some Eastern Colorado locations, too. Pure gas for 87 and 91, and E10 for 89. In the past at least, the 89 "gasohol" was cheaper than 87 regular.


I saw this a decade ago in South Dakota and Montana.
E10 89 was cheaper than E0 87.
I'd bet that the reverse is true at current oil versus ethanol prices.

 

[Oregoonian]

Originally Posted By: HosteenJorje
89 E-10 is common at many Nebraska locations. I use SHELL 91 unleaded since the bottom fell out of crude oil. Probably go back to 89 E-10 when crude costs go back up.

IMO....using a gasoline that is higher than what you car manual calls for.....is a waste of $$$....and could possibly be harmful to your vehicle.

 

[eljefino]

I recall dodge ads mentioning "peak horsepower" and some verbiage in the owners manual about 89 suggested but 87 being fine. Assumably, they have a knock sensor system that tunes for either fuel map.

Recent (2013) Hemis call for 89:

http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=34244

 

[A1O]

Yea I remember the day of leaded 89 gas. And I didn't know any manufacturer recommending 89 for their vehicle. I do remember certified gas stations selling 90 octane rated gas for along time. And most of the tanks at the gas stations I go to have three separate tanks one for each grade. I just thought why produce and sell a product that has no real benefit. Guess that's why I'm not in the oil business.

 

[Wolf359]

Originally Posted By: A1O
Yea I remember the day of leaded 89 gas. And I didn't know any manufacturer recommending 89 for their vehicle. I do remember certified gas stations selling 90 octane rated gas for along time. And most of the tanks at the gas stations I go to have three separate tanks one for each grade. I just thought why produce and sell a product that has no real benefit. Guess that's why I'm not in the oil business.


Couple of reasons. First is profit, margins are higher on the higher octanes. Also they do have a benefit. On older cars with carbon build up, it may only require 89 to stop pinging instead of 93 or 91 so it's a little cheaper for the consumer to fill up using 89 instead of paying more for super. But they could do the same thing with just mix some super with their regular tank.

 

[Malo83]

Run 89 in my 2008 Malibu LTZ 3.6, manual states 89 for better performance, 2015 GMC Terrain with 3.6 also fed 89

 

[Garak]

Originally Posted By: Gasbuggy
Every station I'm aware of in the U.S. uses independent tanks for their 3 grades, you can count the caps in the parking lot.

Here, some oil companies specifically advertise a mix done at the station.

Originally Posted By: Gasbuggy
It gets two kind of buyers, the guy who should run 87 but likes to treat his car to a high grade, and the person who should run 91 but is cheap.

That, I'd believe.

 

[HerrStig]

There are are lots of older cars with just enough carbon in the chambers to raise the octane requirement just above 87, and 89 prevents timing retardation, or to put it another way, a carboned 87 octane engine can run full advance on, say, 88.5.
The knock sensor is a wonderful thing.

 

[DBMaster]

Before gas started including 10% ethanol here I had to run my 89 Accord LXi on 89. It would knock on 87 due to the slightly higher compression of the A20A3 engine v. the A20A1. After the ethanol was added the octane was raised just enough to allow me to run on 87.

As an aside, I noticed a 7-11 in McKinney that has four different octane levels, 87, 89, 91, and 93. I know it's just differing blends from two tanks, but wow.

 

[SHOZ]

Originally Posted By: DBMaster
Before gas started including 10% ethanol here I had to run my 89 Accord LXi on 89. It would knock on 87 due to the slightly higher compression of the A20A3 engine v. the A20A1. After the ethanol was added the octane was raised just enough to allow me to run on 87.

As an aside, I noticed a 7-11 in McKinney that has four different octane levels, 87, 89, 91, and 93. I know it's just differing blends from two tanks, but wow.
Had a '79 4 cly Mustang that was the same way. It knocked like crazy on 87 but then they started using the E10 and it went away.

 

[Wolf359]

Originally Posted By: DBMaster
Before gas started including 10% ethanol here I had to run my 89 Accord LXi on 89. It would knock on 87 due to the slightly higher compression of the A20A3 engine v. the A20A1. After the ethanol was added the octane was raised just enough to allow me to run on 87.

As an aside, I noticed a 7-11 in McKinney that has four different octane levels, 87, 89, 91, and 93. I know it's just differing blends from two tanks, but wow.


I've seen some before like that, even one that had 5 grades. I think the lowest was an 86

 

[DBMaster]

I've seen this setup in Colorado also (Dillon). the lowest grade there is 85. That's a function of altitude. All the grades are lower than here.

 

[fdcg27]

Originally Posted By: A1O
Yea I remember the day of leaded 89 gas. And I didn't know any manufacturer recommending 89 for their vehicle. I do remember certified gas stations selling 90 octane rated gas for along time. And most of the tanks at the gas stations I go to have three separate tanks one for each grade. I just thought why produce and sell a product that has no real benefit. Guess that's why I'm not in the oil business.


89 octane is actually the recommended grade for my old BMW and was for an old Mercedes we had as well, so some manufacturers did recommend the grade.

 

[Jarlaxle]

Originally Posted By: RISUPERCREWMAN
Originally Posted By: dave1251
Nope. On my truck 89 octane is recommended but 87 can be used.


My 5.7 Hemi in my truck says the same. I just pit in 87 & call it a day. It does not ping at all.


This time of year, probably not...but 89 octane will probably be worth some mileage in the warmer weather. My Hemi Magnum took about a 1-1.5MPG hit in the summer on 87.