# Higher Octane = More Power?



## bartony

Time has come to give the Honda Accord Hybrid a drink of "pushwater", and again, I find myself debating, "Get 87, 89 or the 91 octane gas?" Does anyone here feel that a higher number gives more power? I seem to see more pep with one like my favorite, Shell V-Power, but yet, sometimes, I'm unsure. I once tried Exxon gas, knowing (thinking) it was always the best around, but in that old car I had, it would hardly untrack on Exxon! I currently bounce back and forth between Conoco (Phillips) and Shell fuel. 

Any opinions out there? 

Thanks~


----------



## bruiser

In your car, going to a higher octane gasoline probably wouldn't help anything. Just cost more. Performance car engines benefit from the higher ratings, the average car doesn't.


----------



## bartony

Thing is, this IS a high performance car with over 255h.p. So, I guess that's why the higher octane helps. 

Thanks-


----------



## bartony

I "guess" it's high performance--been outrunning everything in town for some reason.:wink: I forgot to mention it's the V-6 Hybrid, not the four.


----------



## bruiser

What does the manual say?


----------



## bartony

It says, and I forgot to post it, to run 87 or higher for it. I put in the good ol' V-Power again today, and it seems to like it pretty well--moves good. Guess I'll stay with what it does good with.

Thanks~


----------



## bruiser

If you had a scan tool, you could look at some things, such as timing and knock count(s), and compare 87 to 93 etc. That would be real info.


----------



## bandit109

I'm not sure if they get much more power being stock, but mine seems to run/idle smoother w/ premium. This past weekend I changed to mobile 1 5-20 syn. oil, put a k&n air filter on it, started running premium fuel, and reset the cpu to see if mileage/power increases. The week before I ran 3 tanks of fuel w/ 23,24.5,25.5 mpg 87 octane. The first tank of fuel this week was 23.8, fill er up again tomorrow to see the 2nd. It definately runs better, the 2nd tank should be more accurate, more consistent driving w/ last week. (it's an 03 accord v6 coupe that sees a ton of driving)


----------



## cresing

You should always go for what the manufacturer recommends for your car. You are not going to notice much of a difference if your car is made for 87 and you start using 93 octane. Now if you have a car the is designed for 93 or higher and you are using 87...then yes you will notice a difference and it is not good for your car to be running on the lower octane. 

Take my car for example Toyota MR2 Turbo. It requires the highest octane available. If I were to put in 87 octane I would get knock. That is because my engine would compress the gas more before it ignites. If you put regular gas in a car that requires premium, the gas will prematurely ignite when it’s being compressed. Not a good thing. So you may notice a slight (i mean very slight)gain in power and a little bit better gas mileage but not much. You will notice a probably notice a bigger difference if you are using below the recommended octane.

Check this out...its a pretty good write up about gasoline and octane ratings. It's PDF

http://www.oregon.gov/ODA/MSD/docs/pdf/gas_octane_guide.pdf


----------



## bandit109

Good doc. --- man . I'm stubborn though, gonna try it for a few tanks & see what happens . Didn't quite use a full tank today ....... so I'll fill up tomorrow .
Could be crap -- but I read that the newer hondas could sense the increase in octane & advance timing accordingly (cant remember the address or i'd post it). Figured why not try & see, obviously I dont have any hard evidence other than fuel mileage & how the car feels driving ...... Could just be in my head though !!


----------



## bandit109

Ahhhh -- found it .

Check this out -- according to a honda engineer. says premium adds 10 hp 10 ft lbs :4-dontkno 

http://www.usatoday.com/money/autos/reviews/2002-08-01-accord_x.htm


----------



## cresing

I wouldn't doubt that some cars now could tell the difference in octane and advance the timing with how crazy the stuff cars can do now. But 10hp seems like an awful lot on just a higher grade octane. But it would be really hard to tell what the gain would be unless you decided to dyno it on the different types of octane. But hey if it feels like the car is running better to you and you don't mind spending the extra money to get the higher octane why not...don't think it will hurt. Good find though..interesting.


----------



## Monterey Jack

Use the lowest octane you can use without getting knock. No benefit to running 93 when the car runs fine on 87 other than to pad the oil companies wallet. KNown a few people who put 116 octane RACE FUEL in their sportbikes thinking it would give them more power. Well they actually LOST power. I've put 87 in a freaking Viper and it ran fine. Pushed the wrong button at the pump and didnt realize it until I put the nozzle back. No knock (which is surprising considering the performance capability of this motor) all through driving to empty the tank. That included quite a number of on the gas "fun sessions". My bike on the other hand, runs like its on 3 cyl with 90 or less. One disadvantage of having a very high compression motor.


Funny though some brands of 87 runs worse in my truck than other brands of 87.


----------



## bandit109

DUDE -- you have a viper ........ ray: ray:


----------



## bartony

That's one interesting article, Bandit! That being just on an '03, it could stand to be correct on an '05 like this one. This one we have is the V-6Hybrid 255hp. So, that may prove why it seems to kick better on V-Power Shell. I never want to be a braggart or blowhard, but I'll swear, sometimes, I have to watch it on the pedal--I'll have these Michelans screaming for mercy if I come down too hard on it, using the V-power. Guess I'll stick with good ol' V-power. Kind of a fun car to have.


----------



## Monterey Jack

bandit109 said:


> DUDE -- you have a viper ........ ray: ray:


Dude they arent that expensive anymore. Used ones are down to $25K if you look. The 00 GTS I bought was only $34K. Had to do body work and paint it due to previous owner being an idiot. Sold it 2 yrs ago. Got bored with it and just prefer basic trucks. 

THen again the list of "exotics" I've driven (and damaged) is rather lengthy., *Porsche 911 Clubsport racer (destroyed during testing), 
*Countach LP400S (cousins. Bought from a police auction), 
*Holden HSV Commodore race car (rolled it, testing again), 
*89 Ford Falcon EA racecar (got involved int a 2nd lap crash at Ipswitch), 
*89 Skyline GT-R32 (stock. Dont see why everyone drools over it. They arent that great. Yeah its about vette quick, but at 190kmph, approx 120mph, it falls on its face due to computer limits. skimmed a wall at the track I test drove it on near the end of my last session when the limiter caused the car to stumble coming out of a corner), 
various open wheeled racecars (4 of which I sent to salvage), 
*a trans am ford mustang (my team mates car), 
*pre production test Viper GTS (wicked fast, guy I knew was in management at Dodge. Got to play with one on the street in 95 before they hit the floors in 96), 
*BMW M1 Procar (sunday track drive, no high speeds), 
*1966 GT-40 MkII (a real one. not a kit car. Was my bosses car and he wanted pics of it on the track. I never felt so nervous driving on a track ever.)
*Couple others of his collection also. Ironically I never had a chance to drive a corvette.:laugh: Gotta love being a road racer. Got to drive alot of cars over alot of tracks. Now retired. Crashing is hurting too much and getting to old (knee problems make it hard to drive competatively anymore. ).

Forgot to add bandit that I'm almost 40. Had a little more time to get to play with various cars.:grin:


----------



## bandit109

Thats awesome ------- i've never driven on a road course , but have on a few dirt tracks. I have a few friends that race NVRA so i'll drive occasionally . I've helped them with body work on 4 or five of their cars . 56 Ford Falcon, 57 Ford Fairlane, 60 Ford business coupe ( chevy motor :3-thumbup ), couple of others I can't remember exactly what they were. I'll see if I can post some pics.

The most "exotic" thing i've driven was a cadillac Allante that I had for a bit. -----the v-8 version. Had a 94 vette ( parents ), & 94 camaro also. The camaro had some "extras" if ya kno wha I mean !! It would rip a vette. That falcon had a "busch" racing engine in it, probably 650-700 hp. They never let me near it !! The business coupe was my baby -- chopped tha top 4" & shortened 12" w/ about 600 chevy horses under tha hood . It would handle better than the other cars though, so it won a few . It was literally a chevy in a ford body !! Poor engine --- I could almost watch it trying to outrun tha rust !!

My list of k.o.'s include the allante, 01 gmc conversion, 99 denali, & a 2000 yamaha warrior that I hit a freakin' plow out in a field. My other 5 lives were used up in close calls ! Again i've got some killer photos if I can scan & post them . Oh yea, forgot the 90 toyota pickup i drove off a cliff -- literally ( was about 18 ft ) 4 wheelin' in TX when I lived out there 4 a bit.

I'm about 30 -- so believe me -- I feel ur pain. It was all fun though !! least nobody was seriously injured !! :laugh:


----------



## bandit109

Almost forgot --- 26.679 mpg. I'll run a couple more tanks to get an avg.


----------



## Volt-Schwibe

bandit109 said:


> Could be crap -- but I read that the newer hondas could sense the increase in octane & advance timing accordingly


this is not crap. bit of news, almost every fuel injected+electronic ignition car can do this.

there is a sensor on the block, strategically located on part of the housing, that acts as a bell to amplify this knocking, and the timing will advance accordingly.

but, in retrospect, this is not to compensate for different fuels.

according to the first year college automotive book, that is to "prevent the eventual mis-timing of the engine, as parts wear out." 

also, octane has nothing to do with power... the high school level small engines books even cover this, and i am amazed at how many mechanics don't know this.

octane, refers to a fuel's tendancy to explode, rather than burn. a low octane fuel, will will burn more violently, releasing it's power sooner than a higher octane fuel. a high octane fuel is more stable, and burns more slowly.

_the fact is, no modder knows your car better than the people who built it_, so i 100% agree with


cresing said:


> You should always go for what the manufacturer recommends for your car.


 your car's manufacturer spent a serious amount of money, paying people with years of experience, to decide exactly which fuel to use.

there isn't really anyone that knows these engines better than their makers, so it's best to follow thier advice.

using a fuel with octane too low, can lead to excessive scorching on the faces of the pistons, and can even burn through them.

using a fuel with too high of an octane, can lead to "late burn" where the fire is still occuring during the valve lash, and will eventually burn out the exhaust valve seats and the exhaust valves themselves.


----------



## bandit109

so is that why the car seems to run smoother w/ higher octane ( less volatile ) ? also filled up again today 25.679 mpg . seems to get better mpg anyway . not arguing, just curious . I could see it being a problem w/ an extreme octane rating, but to go to 87 to 93 ?? dont wanna hurt anything !! thx for tha info !!


----------



## Monterey Jack

bandit109 said:


> so is that why the car seems to run smoother w/ higher octane ( less volatile ) ? also filled up again today 25.679 mpg . seems to get better mpg anyway . not arguing, just curious . I could see it being a problem w/ an extreme octane rating, but to go to 87 to 93 ?? dont wanna hurt anything !! thx for tha info !!



Some will. Even two cars built right after eachother might act differently with premium. One might like it, the other might not.


----------



## crazijoe

Volt-Schwibe speaks the truth. This is why in older muscle cars, with domed pistons and 13 to 1 compression ratio, needs to use high octane fuel. The fuel burns more slowly so that it can propagate over the dome. 
Hot spots in the combustion chamber is also a reason for pre-ignition. The quench area in the combustion chamber will tend to create more heat because of the compression. Aluminum engine components, such as heads, can relieve some of this because of its ability to remove heat faster. 
A good effecient combustion chamber design, such as a hemisherical head, will allow the air fuel mixture to swirl around all parts of the combustion chamber for a more even burn.
It is not uncommon for todays engines to use a higher compression without the need for higher octain fuel. This is due to the effecient design of the combustion chamber, electronic spark timing, electronic fuel metering, and the use of metals that displace heat quicker. 

Quick note: The computer in your vehicle will adjust the performance of the engine typically on the way you drive. I had a friend that used to drag race a Corvette in a Stock class at a sanctioned 1/4 mile track. He always won in his class until everyone found his secret. After every run, he would disconnect the battery. This would erase the memory in computer and with the default settings, the computer would have to relearn the way he drove. 

If you really think using a higher octane fuel than what the manufacturer recommends, gives you more power. Take your vehicle to a shop with a chassis dyno and actually find out. 
To me, it's just a mind game.


----------



## bartony

Guess I have a vivid mind. All I know is the tires wouldn't scream on low octane as much, with high, they do, plus overall better performance. Whatta dreamer I am! I just know the performance differences I have noticed. This was so on even a 4 cylinder car. The last 3 cars I've owned have done better on high octane. I can't help it, so must be Shell makes it better--that's what I buy. As I said once already, the book says to burn 87 *OR HIGHER* for the 255hp (more now with the K&N filter)Honda V-6 Hybrid.


----------



## bandit109

maybe in some weird sort of way I just wish my honda was a vette -- then it would need 93 octane fuel :woot: . guess we could change the thread to "people who think their car gets more power w/ 93 octane fuel" kinda like a support group .

............."Hello my name is chris & I use 93 octane in a car made for 87"........

there..........

I said it...........

:laugh:

like on old friend told me " if it feels good do it.............if it feels real good do it twice !!"


----------



## bartony

:grin: With ya' there, Bandit! They're about to make me start feeling guilty for burning high octane. I may try a tank of low octane just to settle some nerves on here.


----------



## bartony

I wish I could say my car slows to a crawl on high octane, but that would be lying. Sure can't help it, if it helps it!:laugh:


----------



## crazijoe

Don't want to make you feel guilty. Your owners manual states 87 or higher. That just means don't use anything less than 87. Remember, back in the days of the muscle car, high octane was 95 or 97. nothing like we have today. 
Just don't use anything less than 87. I have seen stations in other states with 85 octane fuel so there are lower octane fuels around besides 87.


----------



## bandit109

lets put this one to bed & have a :beerchug:


----------



## manofsorrow

honestly 255 hp or whatever you have isnt really all that impressive. Also to my understanding if you can run 87 octane without any problems you should stick to 87. If you run fuel with a higher octane that you need you can force your vehicle to run in a rich/lean situation wich isn't great. As for performance differance. Take it to the track and have some fun on the 1/4 mile. make sure you run the tank fairly low before switching grades and than once you switch grades run it low and fill it again to get the most accurate results. If you dont see any gains on the 1/4 mile than you dont have any performance gains. Also if running higher octane would give you 10 extra hp (unlikely) if I remember correctley that would only give you a gain of 1/100th of a second in the 1/4 mile or less. Also if you think you have a performance car you should get at minimum mid 13's in the 1/4 mile.


----------



## bartony

Oh really! Why am I outrunning everything in town? You misquoted me-- I did not say it added 10 h.p. The K&N Filter could do that by itself.

I can't help it if I bought a top performing car. I won't lie and say it crawls like a turtle when it runs like it does. 

I just got through losing my dad a week ago, and here I come back seeing my car knocked. Thanks, but not! I'm not an idiot teenager so you won't see me trying to tear my car up on a drag strip either. It gives me enough thrills here in town beating everything on the streets.

I'll be leaving the forums. Nothing gained here.


----------



## bartony

Well, this is fine--I can't even edit or delete on this thing.
Oh well--No regrets, but I wanted to add I made the same mistake myself, 'sorrow', I too underestimated what Hondas put into their cars. We were coming back from my dad's funeral Sunday and I cranked it up to around 105mph, and the pedal was far from the bottom--tach read around 2500, so I can't complain. It may not make the 160 the speedometer goes to, but it doesn't sit still either. I don't know if the Michelins are made for high speed or not, but I need to stay off it to stay alive.

Anyway, a few years ago, you couldn't have given me a foreign car--always bought U.S. made. I became educated about foreign makes, test drove both American and foreign and decided on the Accord Hybrid. Now, I wouldn't have one of these U.S. also-rans. Love the economy too. Averages around 34 on the highway, but still just a bit over 5,000 miles on it. I remember test-driving a Pontiac. Sloppy, sloppy! I couldn't believe the lack of response. This is really just a family sedan, but runs like the wind. I didn't build it, so I can't help that. I dont "think I have a performance car", son, I know I do. Can't help that either. I don't need gauges and meters to tell me that. 

Anyway, I do appreciate the input despite the appearance of my other post.
I'm still seeing better perf. with Shell V-Power. I've been thinking of trying Exxon, but the time I tried it on another car I owned, it ran really whimpy on the stuff, so jury's still out on Exxon fuels. 

Exiting thread & forums~


----------



## Volt-Schwibe

we here at techsupportforum hope that you do not let the opinions of one member run you off.

there is 99,999+ other members here.

one member is not even 1/10 of a percent.

it's also impossible for everyone to agree all the time.


----------



## bartony

The small percentage says I wouldn't even be missed, but I appreciate the wish to see me stay on.

Actually, I lost my dad a little over a week ago, and things have been tough lately. I've been missing like a Ford spark plug, on many forums, but will be drifting in more as time passes and I recover from my loss.

Talking about octane again, I may just go middle of the road, and start buying the middle octane (89) of Shell. I'll get some kick and not overdo it that way, I suppose.:wink: 
Talking later~


----------



## Fightgar

insensitive totally uncalled for comment,and not acceptable on this forum or any other


----------



## crazijoe

Fightgar said:


> You lost your dad? What, so because you're an idiot and can't even locate the man who fathered you, that makes your point more logical?


Ok, that's out of line.


----------



## Volt-Schwibe

yes it is out of line.

it is not really fair to make fun of someone's misfortune.

i am locking this thread down now, since the original subject has been well discussed, and now it's heading downhill.


----------

