I don't think there's a standard in octane numbers across the nation, so just pick the category that's the closest to the one you use the most. If you use something other than 87, can you tell us why? Thanks. :notworthy

For me, I've been using 87 octane since day 1. :thmsup:

87 octane regular. Same as I have always run in our Honda V-6's. I don't see the need to spend the extra money on premium. We usually don't push our cars to the limit or drive them hard at all so I don't think I would even notice the difference in octane.

I generally drive hard & nearly all in town..... Hey, this current tank I have over 19 mpg!!! Aren't you proud of me!?

Somewhere, there's a good thread on what octane is, why higher octane is needed for high compression engines, and why your Accord does not benefit from it.
Happy searching :thmsup:

I found a write up:

Accord I4 is 9.7:1 the V6 is 10.1:1 according to the Honda site....so this would be the current model. Your owner's manual would have your's.

FUEL OCTANE SELECTION

GOAL:
To assist students in becoming wiser consumers of gasoline and enable them to select the proper octaned gasoline resulting in an energy savings as well as a monetary savings.

OBJECTIVES:
Students will:

1. Realize that proper fuel octane selection can change MPG.

2. Recognize the economic benefit from proper fuel octane selection.

3. Understand that it takes more raw crude to refine higher octane fuels.

LESSON/INFORMATION:
Fuel octane requirements for gasoline engines vary with the compression ratio of the engine; diesel cetane requirements also vary with the compression ratio. Engine compression ratio is the relative volume of a cylinder from the bottom most position of the piston's stroke to the top most position of the piston's stroke. The higher an engine's compression ratio, the greater the amount of heat generated in the cylinder during the compression stroke.

Posted octane numbers on gasoline pumps are a result of testing fuel performance under laboratory and actual operating conditions. The higher the octane rating on fuel the less volatile (evaporative qualities) and the slower the fuel burns. Higher octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude.

If fuel octane is too low for a given compression ratio, the fuel prematurely and spontaneously ignites too early and the fuel charge EXPLODES rather than BURNS resulting in incomplete combustion. The net effect is a loss in power and possible engine damage. The operator hears an audible "knock" or "ping", referred to as detonation. Detonation may vary from a faint noise on light acceleration to a constant, deep hammering noise while driving at a constant speed. Improper timing adjustments, vacuum leaks, or excessively lean fuel mixtures may also cause detonation.

Many vehicle owners believe that higher octane fuels are better for their vehicles since they are labeled "PREMIUM." The logic is that since it is a premium fuel it must be better. In reality, the premium label originates from the higher cost to refine and the resultant higher retail cost. Some refiners label their high octane fuels "SUPER." Some owners think that these fuels will make their vehicles more powerful. Only engines with high compression ratios can deliver all the potential energy from higher octane fuels! Always consult the manufacturer's octane recommendation to determine the proper octane requirements for any given vehicle. Generally, engines with compression ratios of 9.3 : 1 or less will safely operate with unleaded 87 octane fuel. Engines with higher compression ratios usually require higher octane fuels.

Many owners who operate vehicles designed to operate on 87 octane fuel experience ping and knock. They usually "fix" this problem by purchasing the higher priced, higher octane fuels. Most owner's manuals indicate that some light and intermittent ping is normal but that heavy or sustained ping or knock should be attended to by either purchasing the correct octane fuel or servicing the engine.

Most fuel refiners blend fuels for geographic areas and adjust their blends seasonally. These blending techniques compensate for the decrease in oxygen content with an increase in altitude and compensate for volatility during the warmer or cooler seasons. Significant ambient temperature changes (40 degrees Fahrenheit) or altitude changes (4,000 feet) may cause some serious engine detonation. This problem is usually corrected by filling the tank with "local" fuel that has been properly blended for season and altitude.

ACTIVITY:
1. From the owner's manual, determine the octane requirements for a personal or family vehicle. If the owner's manual is not available, telephone, write or visit a franchised dealer for that vehicle to determine the appropriate octane fuel for that vehicle.

2. Make sure that the tank level is at ¼ or less before beginning this activity. Perform the "MPG test as outlined in the "Fuel Mileage Calculation" guide with the highest octane (91+ octane) fuel available for two sequential tanks. Calculate the two tank MPG. On the work sheet, note any extraordinary engine noises or performance problems during this test and note the cost per gallon.

3. Repeat step "2" for the next lower octane fuel (89 octane). On the work sheet, note any extraordinary engine noises or performance problems during this test and note cost per gallon.

4. If applicable, repeat step "2" a third time with lowest grade fuel (87 octane). On the work sheet, note any extraordinary engine noises or performance problems during this test and note cost per gallon.

5. For each grade of fuel, use the MPG and cost per gallon to project the fuel cost to operate this vehicle for 10,000 miles.

CULMINATING ACTIVITY:
1. Prepare a short report highlighting the need to determine octane for the selected vehicle.

2. Using your MPG data for each grade of fuel, compare the operating costs for ten years at 10,000 miles per year. Assume fuel costs $1.25 for 87 octane, $1.45 for 89 octane, and $1.65 for 91+ octane.

FUEL OCTANE WORK SHEET
1. Octane recommendation (source: owner's manual): _______

2. Fill tank with 91+ octane fuel; odometer reading: ______

3. Fill tank with 91+ octane fuel; odometer reading: ______
Gallons purchased: ______
Traffic Mix: ________________________

4. Fill tank with 89 octane fuel; odometer reading: ______
Gallons purchased: ______
Traffic Mix: ________________________

5. Fill tank with 89 octane fuel; odometer reading: ______
Gallons purchased:______
Cost per gallon: ______
Traffic Mix:________________________

6. Fill tank with 87 octane fuel; odometer reading: ______
Gallons purchased: ______
Cost per gallon: ______
Traffic Mix: ________________________

7. Fill tank with 87 octane fuel; odometer reading: ______
Gallons purchased:______
Cost per gallon:______
Traffic Mix:________________________

8.

Type Fuel Cost/gallon MPG Cost for 10,000 miles
91+ octane


89 octane


87 octane


INFORMATION CHECK
Place a "T" before the statements that are true and an "F" before the statements that are false. After each false statement, explain why it is false.

_______1. 91 octane fuel has more potential power than 87 octane fuel.

_______2. To release all the potential power of 91 octane gasoline, it is necessary for an engine to have a compression ratio higher than 9.3 : 1.

_______3. Any gasoline engine will efficiently burn any octane fuel.

_______4. The engine's compression ratio is the most important factor in selecting gasoline octane.

_______5. Posted fuel octane ratings are a result of testing fuel in the laboratory and under actual operating conditions.

_______6. Diesel engines require a low octane fuel.

_______7. Engine knock or ping is always a result of poor quality fuel.

_______8. Gasolines are seasonally and regionally blended.

TEACHER'S NOTES
This is an important energy saving activity for students. Over the years, our society has somehow gotten the misnoma that a "Premium" grade fuel is better for a vehicle than a "Regular" grade fuel. Most vehicle owners never refer to their Owner's Manual to determine the acceptable octane fuel for their vehicle. Additionally, when a vehicle begins to knock and ping under acceleration, many owners apply a "quick fix" by switching to premium grade fuel. It is true that excessive and continued pinging and knocking is harmful to an engine and this MUST be attended to immediately or serious engine damage will result. Very few recently manufactured vehicles require premium, high octane fuel. To operate these vehicles with lower than required octane fuel could lead to immediate and serious internal engine damage. Most engines that do ping or knock on light acceleration do not need premium fuel; these engines need proper servicing such as timing adjustments, repairing vacuum leaks, or servicing emissions control valves. To operate a properly tuned engine designed for 87 octane with 89 or 91 octane fuel will only increase the cost of operation. No additional power, fuel economy, or durability will result from the higher octaned fuel.

ANSWERS TO INFORMATION CHECK:
3. False. To efficiently burn any fuel of any octane, the compression ratio of the engine must be high enough to release all the potential fuel energy.

6. False. Diesel engine fuels are rated in cetane numbers, not in octane numbers.

7. False. Engine knock or ping may be a result of too low an octane rating for that engine's compression ratio; most engine knocking and pinging is a result of an out-of-tune engine or emissions control servicing

Nice post princess! It's going to cut down the number of times I need to repeat some of the info in it. :thmsup:

Only reason why I made this poll is to see how many people are using higher octane gas in this forum. I, for one, don't think that the benefits of higher octane gas would outweigh the costs unless 91+ octane can get me 5mpg more in the city!

I, for one, don't think that the benefits of higher octane gas would outweigh the costs unless 91+ octane can get me 5mpg more in the city!

Very subjective and touchy topic. Some people frankly don't care and will pay $$$ for premium because it makes their car run 1% smoother, and some people will run 87 even if it pings every other day.

Since I'm the only one that's voted for the high octane..... :dunno: seems like most are happy with the other.

I can feel the difference in the V6. When he puts that occational lower grade in & don't have to be there to know it's been done. Then again I can tell when he's been driving it too.... that tranny learns him. It's actually fun to get it back in MY hands.... the shift is different & it feels peppier. I remember why I insisted on a V6!

Road trip......I'll let you all know if the mileage is the same for us.

I'm going on another road trip to NY next month. We'll see how my mileage goes. The last time I made that trip, I got an average of 29mpg with 5% local driving and only 1000 miles on the engine. I'm expecting my mileage to go up to about 33mpg! Maybe it's high expectations, but we'll see. :)

In the refining process, fewer gallons of higher octane fuels are yielded from a barrel of raw crude.

FWIW, a barrel of crude oil will also yield. . .
- more diesel than gasoline (so why's diesel not less expensive?)
- more leaded than unleaded gasoline (saving the planet ain't cheap)

FWIW, a barrel of crude oil will also yield. . .
- more diesel than gasoline (so why's diesel not less expensive?)

Diesel fuel gets taxed like crazy. I think CA diesel is like 25 cents or 25% taxed.

diesel stinks. :lmao:

in the TL, slightly different, I just switched to 93 to eliminate spark knock u :lmao: under low rpm load. spark knock is gone, but I can't say I can tell any difference in power or my documented fuel ecomony.....

I think you 87 people are crazy!

91 and only every 91. (As per the sticker on fuel door)


Oh, and in NZ it's either 91, 96, diesel or nothing.
That's all you can get here.

I think you 87 people are crazy!

91 and only every 91. (As per the sticker on fuel door)


Oh, and in NZ it's either 91, 96, diesel or nothing.
That's all you can get here.

I believe NZ and most of Asia uses either 1) leaded fuel or 2) only one way to calculate octane (ie. not RON+MON/2, only one of them).

I believe NZ and most of Asia uses either 1) leaded fuel or 2) only one way to calculate octane (ie. not RON+MON/2, only one of them).


I don't think people in Oceania or Asia have been able to get leaded fuel for ages!

Everything is unleaded!!

And... Well, 91 and 96 is what it says ont he pumps.

(And it can be $80-tank and we somehow get 350-400km on each :paranoid: )

So tempted to try 93 octane for the first time yesterday! There was an Exxon station around where I work that brought its prices down to $2.49/ $2.59/ $2.69 (LOL, OMG, WTF :LMAO: )! Even the Hess around here was still at $2.51/gall for regular! I filled up my tank with regular, but if i was closer to empty, then I would've probably tried 93 octane.

I believe NZ and most of Asia uses either 1) leaded fuel or 2) only one way to calculate octane (ie. not RON+MON/2, only one of them).



Even my former home country phased out leaded gas... It's gone!

Only people that really use leaded gas are pilots.

Theres an Article from Can and Driver when they dynoed a '02 Accord V6 and it lost 10hp on premium fuel

Theres an Article from Can and Driver when they dynoed a '02 Accord V6 and it lost 10hp on premium fuel
I've read the same thing but heard it GAINED 10 hp on premium...

That's for the new V6. The old J30A1 did not like premium fuel.

Hmm, I filled up my first tank of gas in my new car(Chevron 89 octane) and it just doenst feel the same as it did with the first tank(from the dealer).. Ill try BP next time on the same octane and see if I feel any difference. The car is more sluggish, I feel as if there is less torque, but the car only has 360 miles on it, and im taking it slow anyways.. I have lots of time to find the right gas :)

Switch back to 87...89 is not as easy to ignite.

Try diesel...seems to be working great for me. :thmsup: :thmsup:



....


...



Just kidding. :paranoid:

Switch back to 87...89 is not as easy to ignite.

Is that true just with 89? I usually use 87, but it was less than a 10 cent different so I figured why not. What about using 91 would that cause the same type of problems?(just curious)

Actually I just noticed you have a V6...things might be different. I don't know how to explain the power loss, but it's true that with higher octane, the fuel is harder to burn. Octane is basically a measure of how easily the fuel ignites. In a "hot" engine with high HP, you have to use high octane because otherwise, the fuel will ignite too early and you'll have detonation and big problems. But our cars are designed to run on 87.

Now, for the V6...there's debate because a lot of people say that the knock sensor can take advantage of higher octane fuel. In that case, the engine could run at better efficiency, so your HP should increase. I personally believe in this train of thought - though it's only a theory since Honda has released no official documents to back it up. A couple Honda engineers have said that their engines are designed to give extra HP with high octane fuel off the record though. So what you might be experiencing is the computer trying to adjust to the fuel. Right now, it hasn't taken advantage of it yet, so nothing's changed but the fuel is harder to burn, so you're seeing a loss of power. But over time, it should all come back...that's my little pet theory at least.

If you notice it still is producing less power after a while...no harm in going back to 87, it's cheaper :thmsup: Each person's results vary, depends on gas station to gas station, brand to brand, car to car, region to region, state to state, weather conditions....just your luck :yes:

Actually I just noticed you have a V6...things might be different. I don't know how to explain the power loss, but it's true that with higher octane, the fuel is harder to burn. Octane is basically a measure of how easily the fuel ignites. In a "hot" engine with high HP, you have to use high octane because otherwise, the fuel will ignite too early and you'll have detonation and big problems. But our cars are designed to run on 87.

Now, for the V6...there's debate because a lot of people say that the knock sensor can take advantage of higher octane fuel. In that case, the engine could run at better efficiency, so your HP should increase. I personally believe in this train of thought - though it's only a theory since Honda has released no official documents to back it up. A couple Honda engineers have said that their engines are designed to give extra HP with high octane fuel off the record though. So what you might be experiencing is the computer trying to adjust to the fuel. Right now, it hasn't taken advantage of it yet, so nothing's changed but the fuel is harder to burn, so you're seeing a loss of power. But over time, it should all come back...that's my little pet theory at least.

If you notice it still is producing less power after a while...no harm in going back to 87, it's cheaper :thmsup: Each person's results vary, depends on gas station to gas station, brand to brand, car to car, region to region, state to state, weather conditions....just your luck :yes:


I see.. good insight.. Well This was the First tank of gas I have filled my car up with.. so the sensors have really not gotten used to any octanes yet. I will try to stay with 89 for a few tanks and see how it goes, overall the cost here will be 90 cents more, and if can help in performance, then 90 cents is a small price to pay. :thmsup:

I've read the same thing but heard it GAINED 10 hp on premium...


I have the magazine right here in my hand. November 2001 Car and Driver

I was wrong, it wasn't 10 hp it was 4hp

The Accord V6 dynoed 147hp on premium and 151hp on regular. There was a decrease of 1.5 percent of its acceleratoin.

The Saab 9-5 Aero which requires premium fuel dynoed. 180hp on premium and 164 on regular. There was a 10 percent gain in accelration.

Mustang GT requires regular. dynoed 191hp on regular and 193 on premium.
2.7 percent gain in acceleration

Dodge Ram V8- Requires regular. Dynoed 183hp on regular and 190 on premium. But also had a .5 percent decrease in accleration

None of the experts could explain why the Accord lost power on higher octane fuel since it did have variable valve timing. But it did.

A BMW M3 was also tested but its computer wouldn't let it dyno properly.

Do we know the conditions though? I mean, if they weren't tested with strict monitoring of all the conditions (temps, humidity, whatever) and also if they weren't given time to adjust...that 4HP could just be a fluke. It wouldn't unheardof for a car to lose 4HP between dyno runs.

I think the extra cost of premium is worth my extra piece of mind.. Whats another dollar or two? :dunno:

Since i filled my car up for the first time myself, i have used 91+-- IDK? I never used it in any previous vehicle, i just figured why not..

They guys at work say that usually in toyota v6's and lexus' they say to use 89+ b/c of the knock sensor and it makes them run a little smoother..

Im not sure if there is much of a difference in the way my car runs, but it sure does run smooth (then again i came from an altima lol)

Mom's bmw-- they say to use 91 or higher, b/c it is a high performance engine.. They also only use Mobil 1 or Castrol in it..
Synthetic all the way for that thing.. and BMW says oil changes every 15k..
Pretty crazy i think... It also takes like 7 quarts or something like that too..

Should i switch to synthetic oil? The guys at work say that now would be the perfect time.. But im not sure if its worth it..