What Octane Do You Prefer?

[firefighterwhite89]

Just curious.

[A18A]

I always used 95 RON in my b20a accord, or 98 RON when it's available and someone else pays for it. dunno what that is in MON though

apparently our 91 is equal to your guys 82 lol

[charliekuney]

I just use 87 from SafeWay because after my 10¢/gal discount it's the cheapest out of all of the gas stations.

[1813mdw]

i put $4 dollars a day of 87octane in my car every morn on the way to work lol.

[Pico]

With the price of gas here in Calif. 87 is all I ever get..and where ever it's cheap

[forrest89sei]

87 From Either Arco or Shell

[cubert]

87 octane in the car, and either 93 or 110 in the bike

[lostforawhile]

the way the octane standard is measured has changed since these cars were built, what was 87 in 1986 today would measure closer to 89, most new cars adjust to the different standard with no issue, but the older cars are kind of hung out to dry, the corn they put in the gas doesn't help either, I think stabil has formulated an additive to help offset the creamed corn in the tank, but i'm not sure of anything that really helps the octane issue

[forrest89sei]

^ Yeah true, In California up to Gas can contain up to 10% Ethanol

[firefighterwhite89]

I use 93 Octane, as it helps reduce ping even more than 87, especially since i've blocked off my EGR valve AND, my Workshop manual, says use 91 RON or higher...Besides the fact Idle and acceleration seem slightly smoother and i get noticably better gas mileage using 93 vs 87. It's only 18 cents more here. Help keep your engine slightly cleaner internally, though carbon build-up is inevitable.
AND, my exhaust is actually 150*-200*F cooler running 93 vs. 87 i noticed on my EGT gauge.

[firefighterwhite89]

^ Yeah true, In California up to Gas can contain up to 10% Ethanol

Luckily, at least 40% of gas sold in AL is ethanol free FTMFW. Screw some ethanol. I'd MUCH rather run Gas/Methanol! lol.

[forrest89sei]

Luckily, at least 40% of gas sold in AL is ethanol free FTMFW. Screw some ethanol. I'd MUCH rather run Gas/Methanol! lol.

BUT it's done us sooo well!

I mean we're using a Food Source in our cars! So Corn Prices are sky high, but Gas Prices are um......... Yeah. Still High! GO CORN!

[mykwikcoupe]

I want to saw all gas in WA state is up to 10% ethanol as well. i try to run 87 most of the time and every rd tank I run premium. I think its ok since i put 700-1000 miles a week in the car. The gas itself really doesnt last very long. Issue is twice a week i climb a 3300ft pass at 90 miles an hour. The car doesnt seem to mind either way.

[DBMaster]

Having had the car since it was new I am actually happy to say that I can run on 87 octane. Until the gas here was reformulated with ethanol I had to use mid-grade to prevent pinging. I have no pings or knocks on the current 87 while I did have them for years prior if I tried to use it.

The drawback, of course, is that I lost three mpg of fuel economy and the engine does not perform quite as well. These are well documented issues.

[Xybris]

I've always used 87 and never had any problems. Over where I am now they only give us 93 (or 91, I can't remember)- I don't know why, maybe for the Nissan ricerfags. Since the earthquake wrecked the refinery it's down to 87 and I can't tell a difference, not like I ever would with a D16 stock.

[Dr_Snooz]

I used to use premium 92, then it changed to 91, so I use that now. I want the engine to stay nice and clean inside and the reduced pinging is good insurance for an engine that doesn't have knock sensors. With gas at this price, what's a few more pennies per gallon?

[gp02a0083]

I used to use premium 92, then it changed to 91, so I use that now. I want the engine to stay nice and clean inside and the reduced pinging is good insurance for an engine that doesn't have knock sensors. With gas at this price, what's a few more pennies per gallon?

exactly, i use 92/93 preferably at wawa or sunoco gas stations. I have found out with my hatch , im getting at least 33 miles on average more with the higher octane fuel. I filled up yesterday even with premium at $4.03 a gallon vs $3.83 for regular, it was about a $2.40 difference for a fill up.

as far as the concern and performance with the E10 blend that's now practically a standard. When our cars were built they used MTBE in the gas, prior to the ethanol blending. They had to phase out MTBE due to its toxicity characteristics. I could go into a lot more , but im not gonna bore you guys to death with scientific junk.

[Oldblueaccord]

I run 2 gallons on E-85 to a tank of 87 octane (E-10) I just pulled a 30.3 and a 30.8mpg. It comes out very close to 30% on a fill up every 300 miles. its 30 miles to work one way and I have 9 stop lights and a 15 mile highway run.



wp

[MessyHonda]

any shell

[Vanilla Sky]

It's best to run the fuel that keeps your engine from pinging or gives the best performance. Higher octane does nothing at all to keep your engine cleaner. Run the lowest grade your car will allow.

[gfrg88]

I'm gonna be pumping 104 ;)

[ecogabriel]

I pump 87 and the car works fine - no pinging.

Based on what I have read here though, I am wondering if 89 octane would make a difference in mileage. Maybe an "experiment" I will run soon.

[lostforawhile]

I pump 87 and the car works fine - no pinging.

Based on what I have read here though, I am wondering if 89 octane would make a difference in mileage. Maybe an "experiment" I will run soon.

it may depend on the area you are in, the formulation changes regionally

[ShyBoyCA6]

i just pump 87 with some fuel treatment every 3000 miles or oil change.

[2oodoor]

I run 2 gallons on E-85 to a tank of 87 octane (E-10) I just pulled a 30.3 and a 30.8mpg. It comes out very close to 30% on a fill up every 300 miles. its 30 miles to work one way and I have 9 stop lights and a 15 mile highway run.



wp

wow, your commute sounds just like mine!
I have heard a lot of opininos and data supported debates on this topic. It seems to vary a LOT between models.
As for latley I use 87 in everything but I did put in 93 in the B20 LX last month and that gas seemed to last a lot longer. That could have been my driving style changed to see how many mpg I could squeeze in general. The 87 I filled up with in the same car last week seems to be going down faster but I won't know pure data till next week.
Big news today is the E15 we're about to get, well believe we already have been getting it wiith out being told.
Will we all have to be using owner poured additives to hold this stuff back from separating and corroding our fuel systems? Could be a rise in sales of that stuff, stockholders.

[Dr_Snooz]

Higher octane does nothing at all to keep your engine cleaner.

Um, yes it does. They put more detergent in the higher grades.

[Vanilla Sky]

Um, yes it does. They put more detergent in the higher grades.

That's not due to the higher octane rating, that's due to extra detergents. Not all brands have the added detergents in the higher grades, either. I try to use Chevron here in town, and Shell everywhere I can get it, so I'm using pretty good fuel no matter the grade.

Unless things changed, E15 is required to be in a separate tank with a separate pump. Not all vehicles can run on E15 without fuel system issues.

[Pnem3]

I use 87. I always thought and heard that from a technical standpoint, octane performance and mileage were tied to compression. Higher compression engines produce more power from higher octane gas because they have more compression. I don't see how our cars can take advantage of that since their compression isn't high enough to need more than 87 octane.

[obdriver6]

I use 87, anything else is a waste of money on these cars, unless you're turboed or have an engine with high compression, as long as you stay away from the cheap places (Billy Bo Bob Gas Station) and go with the good gas (Shell, Chevron, ect.) you should be fine just remember you get what you payed for.

[lostforawhile]

remember in some of the higher grades, they don't add corn, it depends on the station, etc,

[frantik]

i always use 87 never had any problems.. :dunno: Rotten Robbie or Arco for me

[gp02a0083]

Unless things changed, E15 is required to be in a separate tank with a separate pump. Not all vehicles can run on E15 without fuel system issues.

yes our cars will probably have a slight problem with the E15, i can say right now without even putting that stuff in my hatch that you will get junk gas mileage.

anything after 12.5%-13% ETOH (ethanol) causes a sever drop in power, only benefit to having the higher amounts of ethanol is lower combustion temperatures that lead to a cooler running engine. re-timing the ignition would most likely be required to accept E15.

i had a discussion with BISImoto about this when they stated using E85 gave a 4% power increase due to the fuel being used, then they went and said that ethanol has more energy per unit than gas. Needless to say they didn't know they were talking to a chemist

lost is correct as far as the detergents/additives , everyone has a different blend that they use, overall there really similar. My friend used to work for sunoco and told me a lot about the blends they use. Just also keep in mind that gasoline is a mixture of chemicals, many of which you can find in the paint supply section of any store.

[Oldblueaccord]

Ill say this BTU is only part of the equation. Remember 93 octane had less BTU then 87 does but MOST cars get better mileage with higher octane fuel. High power levels and gas mileage don't always go hand in hand in fact I would guess almost never.


wp

[Oldblueaccord]

wow, your commute sounds just like mine!
I have heard a lot of opininos and data supported debates on this topic. It seems to vary a LOT between models.
As for latley I use 87 in everything but I did put in 93 in the B20 LX last month and that gas seemed to last a lot longer. That could have been my driving style changed to see how many mpg I could squeeze in general. The 87 I filled up with in the same car last week seems to be going down faster but I won't know pure data till next week.
Big news today is the E15 we're about to get, well believe we already have been getting it wiith out being told.
Will we all have to be using owner poured additives to hold this stuff back from separating and corroding our fuel systems? Could be a rise in sales of that stuff, stockholders.


Yeah I need to do a highway run and see if I can get a 34 I used to get on long trips. Age of the car, 250 cc injectors,205/50 tires probably don't help.

To be fair also I have the timing advanced some and I can run it all the way advanced without any ping I can hear where as with 89 octane I could hear some ping between throttle on shifts.

wp

[2drSE-i]

yes our cars will probably have a slight problem with the E15, i can say right now without even putting that stuff in my hatch that you will get junk gas mileage.

anything after 12.5%-13% ETOH (ethanol) causes a sever drop in power, only benefit to having the higher amounts of ethanol is lower combustion temperatures that lead to a cooler running engine. re-timing the ignition would most likely be required to accept E15.

i had a discussion with BISImoto about this when they stated using E85 gave a 4% power increase due to the fuel being used, then they went and said that ethanol has more energy per unit than gas. Needless to say they didn't know they were talking to a chemist

lost is correct as far as the detergents/additives , everyone has a different blend that they use, overall there really similar. My friend used to work for sunoco and told me a lot about the blends they use. Just also keep in mind that gasoline is a mixture of chemicals, many of which you can find in the paint supply section of any store.

You will get better power running E85, but you will be burning through it much faster, correct? Ethanol burns cleaner, but also hotter and faster.


If I could get E85 here in OK (without going on our AFB or driving an hour out of my way) I would already be converted and tuned. This gas price nonsense is ridiculous.

[DBMaster]

This is as good an article as any I have read. I became interested after a trip to Colorado during which I noticed that regular was 85 octane.

http://www.squidoo.com/regular_or_premium

As far as E85 goes, it is a known fact that even flex fuel vehicles lose power and fuel economy when they run on E85. About the only thing it's good for is as a "cheap" fuel for high compression or heavily boosted engines.

It appears that the oil companies' marketing efforts are still yielding great results!

[gp02a0083]

You will get better power running E85, but you will be burning through it much faster, correct? Ethanol burns cleaner, but also hotter and faster.


if you are comparing E85 to gas ( no ethanol), or even E10, gallon for gallon you would not get the same energy output with a higher amount of ethanol. Ethanol burns slower than gasoline and burns cooler. This is the primary advantage of ethanol, it will allow the engine to run at a lower operating temperature. This is why they use ethanol and methanol in racing.

Also, and this is what really pisses me off when people say ethanol is soo much better, is the fact that you are basically burning off 1/2 a water molecule ( the OH group in the alcohol) in the combustion reaction. Water takes up a frigging butt load of energy in the combustion, meaning you would have to put more energy into the system to get even a fraction out. Another strong point that is a down fall of ethanol is its hygroscopic characteristic, water is extremely soluble in alcohol ( at least the low carbon chain alcohols). let it sit for a few days, i guarantee that the car will run really bad as it is also trying to burn water.

As far as he rate of consumption, this would be independent issue. This would require remapping the ecu / fuel management system to achieve the proper air /fuel ratio. This would depend on the fuel delivery, ignition timing and compression.

here is a pdf with a chart showing the differences between ethanol , methanol and gasoline

http://iqlearningsystems.com/ethanol/downloads/Racing%20Fuel%20Characteristics.pdf

[2drSE-i]

if you are comparing E85 to gas ( no ethanol), or even E10, gallon for gallon you would not get the same energy output with a higher amount of ethanol. Ethanol burns slower than gasoline and burns cooler. This is the primary advantage of ethanol, it will allow the engine to run at a lower operating temperature. This is why they use ethanol and methanol in racing.

http://iqlearningsystems.com/ethanol/downloads/Racing%20Fuel%20Characteristics.pdf

guess i had it assbackwards then lol

[gp02a0083]

no that fine , its a mistake many people make. :rockon:

[Oldblueaccord]

Amazing I even make it to work everyday.

I remember in 1994 when I changed from r12 to 134a Pep boys told me my compressor would lock up and fall off and that it would turn everything inside to green goo and purple jelly. These are direct quotes the guy sadly still is the manager there I just bought a brake part off him last week. :rofl:



wp

[wh1skea]

I voted 87. I've tried running 93 octane in my hatch and had WORSE gas mileage than I did with the 87 octane. I was very surprised by the results.

[DBMaster]

^^Don't be surprised. You results are consistent with the science. If you use higher "octane" gas than what you need to prevent knocking you SHOULD see lower gas mileage. I put octane in quotes because pump octane ratings are different than the actual chemical content.

[MessyHonda]

^^Don't be surprised. You results are consistent with the science. If you use higher "octane" gas than what you need to prevent knocking you SHOULD see lower gas mileage. I put octane in quotes because pump octane ratings are different than the actual chemical content.

yeah alot of people dont understand that a higher grade just means its a more stable fuel for high compression, high reving and turbo cars. lower grade means gas burns up faster or it takes less to make it spark

[charliekuney]

I just filled up with Shell Premium Plus (whatever their highest octane is). My car runs quieter and seems to be getting better gas mileage, although I haven't been delivering as much...

[Oldblueaccord]

Amazing I even make it to work everyday.

I remember in 1994 when I changed from r12 to 134a Pep boys told me my compressor would lock up and fall off and that it would turn everything inside to green goo and purple jelly. These are direct quotes the guy sadly still is the manager there I just bought a brake part off him last week. :rofl:



wp

Well after this last post I was pissed that gas was up over $3.85 as oil per barrel had dropped sub 100$ so when I went to fill up I only put 3 gallons in. Enough to get home and 2 ways to work. I did this about 4 times never putting more than 4 gallons of E-10 or straight gas as it is here. Beginning of the week I filled the tank again with e-10(87 octane) and filled it last night. 339 miles to 11.6 gallons. 29 mpg. Thats down one mpg from my following 30,30 the previous calculations with 30% ethanol.

Ill be honest It could have been 349 miles I zeroed the odometer and did the math later and my memory has not been as sharp.

Only theory I have is that the car runs a little rich anyway and the mixed gas runs a little leaner,burns better, and I can get about the same mileage. Truthfully I feel no performance difference.

wp

[Australian 86]

i run 98 (ron) which i think equates to 93...
i recently heard of a study (admittedly with newer cars) testing out which petrol got the best k's per $. Supposedly the 98 got the best rating by the tiniest smidgen... not that i really care, just as long as they are about the same.
My logic behind getting the best petrol is;
potentially better k's per $.
fraction more power.
fraction better for the engine.

I think that if this is correct it makes sense to use the better petrol...

I just filled up with shell v-power today and ill see how i go...

[Rebel4x4]

i run 87 i just drove 187 miles to NC stopped at Shell when i got there an it took 5.4 gallons to fill back up. Roughly 35mpg. I Only use Shell gasoline though and they are always pretty close to the Blow Schmo guys. OH YEAH! Octane maybe doesnt neccesarily effect mpg but maybe quality of gas. I knew this old man who owned a gas station in the little town i grew up in and he told me that the "93" gas was no more than the "87" and "89" mixed together with just a tad more detergents not even enough to worry about

[import racer]

I use 89 unless gas price goes down then 93.And I always buy shell,we don't have ethanol around here.

[DBMaster]

This is not totally on topic, but I noticed in the years since I quit using mid grade that the cost differential between the grades has increased to at least 20 cents per gallon. It was 10 cents back when I was using 89 octane. Just another reason not to use higher octane than what you need. If you are using a "top tier" gasoline brand there is nothing to be gained by spending extra money for "detergent." We're not talking about Tide or Cascade here. It is just, perhaps, a slightly higher proportion of different crude distillates (solvents). Top tier gas will keep engines free of deposits, period, in all grades. As I said much earlier in this thread, it's amazing how effective oil company marketing has been. Much like the vaunted 3,000 mile oil change it's an interesting lot of psychological warm fuzzies. Unless you are comparing fuel economy and power output under controlled conditions your evidence is anecdotal at best. When auto publications test these things they do not use commercial gas pumps and the car's odometer. They use calibrated instrumentation. Also, in the real world the drive you took yesterday is different from today. Even if it was exactly the same route and traffic density and you drove it EXACTLY the same way there still could be temperature, humidity, and barometric pressure differences that can all affect fuel economy.

[lostforawhile]

100 Low lead

[2oodoor]

100 Low lead

Low lead and no nox gulf
ol skool tawkin right there.. :beer:


In my truck it gets average of 2 mpg on 93 than 87 but the quality of the gas itself is the key because sometimes the 87 lasts sometimes it goes way too quick.

I usually use 93 in the B20 just because it smells better when it's evaporating from the Weber:flash:and I can run the ignition timing a wee higher for less throttle opening for DD.

[DBMaster]

^What you are saying right here only reinforces my position. More volatile gasolines that did not exist back when all cars had carbs do cause more evaporative loss right out of the fuel bowl. Also, if you change timing, any fuel economy changes cannot be attributed to the gasoline alone. Remember, controlled conditions and instrumentation. Without it a difference of 2 mpg is not significant.

[AccordEpicenter]

where is the C12 option?

[DBMaster]

I wonder, also, how significant the differences are in batches of blended gasoline. We all know that there are differences between "summer" and "winter" gas, or at least there used to be. The stuff in the summer was less volatile to reduce evaporative emissions and vapor lock (like anyone gets that anymore). I'll bet good money that fuel economy changes with a change in the ambient temperature/fuel blend combination. I've opened up my own can of worms.

It's like oil. Whichever one makes you feel better is worth the money. This is in the "sticker adds 10 HP" domain. LOL.

[lostforawhile]

I wonder, also, how significant the differences are in batches of blended gasoline. We all know that there are differences between "summer" and "winter" gas, or at least there used to be. The stuff in the summer was less volatile to reduce evaporative emissions and vapor lock (like anyone gets that anymore). I'll bet good money that fuel economy changes with a change in the ambient temperature/fuel blend combination. I've opened up my own can of worms.

It's like oil. Whichever one makes you feel better is worth the money. This is in the "sticker adds 10 HP" domain. LOL.

big difference between the oil and gas, corn gas doesn't chew up your rockers, need to stick with the oils with zinc or add the zinc, thats pretty much a given since it was taken out, the only engines where you don't have to worry about it are those with roller rockers

[DBMaster]

^That's why I ended up with Rotella T Syn 5W-40 as my oil of choice for the last several years I had the car (diesel engine oils have more zinc). The new car has roller rockers and the oil is 0W-20 syn. It's a really low friction engine, by design.