smoother acceleration
 

I decided to put 91 octane gas in my car for shits and giggles. The main thing I noticed was the acceleration at high rpms (5000-7000) was much smoother. There was a definate difference in the sound of the engine. Best I can describe it was much smoother, more constant. Lets hear some explanations, are there any reasons this would happen?

well do you have k20 type S motor or at least a turbo? if not, putting premium gas in a car design to take regular gas is a complete waste of money

It's my understanding that some higher mileage cars run better on higher octane due to all that sludge and crap that builds up on the valves..injectors..etc.. over time. However, I have 150,000 miles on my '01 and higher octane didn't do crap.

Higher octane isn't bad for our engines is it?? Just not good enough to justify the added cost.

i didnt notice any difernts when i accidentelie put 94 oct in at sunaco...
i was driving my brother eG with b20 the week befor and just didnt think about it. Put it in and then got the tank toped off an look at the $
thats not right stupid gas pump....

I got more. So I went and picked up some octane booster the NOS type. For more shits and giggles. The bottle is suppose to increase octane by 70 points or 7 full octane numbers so I threw half the bottle in half a tank. I figure it would have added a coulpe numbers, so I may be at 95 octane or something. Anyways, there is a difference. I definately seen a difference on my speedometer. 2nd gear with 87 octane I could hit about 80-85 km/hr before rev limiter, now I can almost hit 100km/hr. 3rd gear with 87 octane I could get to between 130-135 km/hr. , now I can almost hit 150km/hr. in 3rd before the rev limiter. I don't know if the gains came from just the 91 octane or from the Octane Booster, I never noticed my speeds before adding the booster. It could be from the gas or the booster or both. Regardless there must be some power gains if I am hitting higher speeds before getting to the rev limiter. I've read lots of the threads saying that there is no power gains from adding octane, i don't believe the skeptics. Has anyone ever put their theories to the test on a dyno? It seems there are alot of "scientists" out there slamming the idea octane adds power, but I think these people are just sitting there talking, not testing. I read my car manual it says, "86 octane fuel or higher" what does the "or higher" part mean? I think higher octane will add some power, it may not be much power but I SAW a difference and that was with a 1.7L non-VTEC engine. Go Figure!

Look, dude, of course higher octane is going to add power. That's what octane is. Higher octane= more volatile.

I think I'm gonna have to call a big B-S on the "Going faster in each gear" statement. Not possible. Just cause you added octane doesn't mean your gear ratios change. Each gear is a number, like third gear is 1.022:1. That's not gonna change because your engine's turning harder. You may get to the redline faster, but you're not gonna go faster in each gear. The only explanation I can offer is that maybe the transmission is shifting sooner. It's hard to tell with an auto.


Jake

I guess higher octane can change the gears in your transmission/end sarcasm

you can't see gains like that, acceleration is based on torque, but top speed for each gear is based on the gearing which can't change unless you change out your transmission or get custom gears made.

EDIT: Jester beat me too it.

Not sure if this may help clear up this discrepancy but I remember watching that Sports Car Revolution show with the Canadian guys and they tested Porche 911 with like 91 and 94 octane. With the lower grade timing was retarded and it gave less hp on the dyno. I'm thinking our ECU's should work the same way and that it will just adjust to the conditions it sees.

ex2k3: haha yeah, I saw that. It's all good.


ronaldo9: Think that could explain his "changing gear ratios?"

You're right on that.. That doesn't make sense at all. I'm not too familiar with km/h but on my EX I can take 2nd gear to roughly 60 and 3rd gear to 80 max at redline.

Yeah, fourth is around 108-110 mph. But that's with a manual, of course.

I'm sure my gear ratios never changed. Show respect. These are my observations. Try it for yourself if you don't believe me.

Maybe I was just driving harder, shifting better or maybe the wind was at my back? I saw it with my own two eyes.

I have tried higher octane gas and I felt absolutely no extra power. It's a waste of money, which over a year at $.20 extra a gallon comes out to about an extra 60-80 dollars a year, that could pay for three oil changes which will do way more than the higher octane gas, or get a gallon each of lc20 and fp60 from lubecontrol.com. There is no possible way to get gains on a stock d17 by using higher octane gas. Now if you had cams and high comp pistons or were boosted that's different.

All higher octane gas does is make the gas harder to burn under higher compression. We don't have high compression (relatively speaking) so what you are effectively doing is not burning all the gas durning the combustion cycle which = less power. The reason it says 86 or higher in the manual is because a lot of people aren't knowledgeable on petrol and the car makers and oil companies rub each other's backs since they both need each other.

Also the rotation of tires is limited by the transmission when it's in gear, even if the wind was against your back or you were driving harder there is no possible way you can reach a higher top speed in a certain gear than before. All I can say is you must not have paid attention to your top speeds in certain gears before and know you noticed them and think there were gains.

I'm not trying to bash you, just sharing knowledge that I have gained on this site over the last two years.

I guess it was a frickin' miracle then. LOL. I thought about it and it doesn't make sense that it would go faster at the same RPM? I dunno. Could have been seeing things like you said? Wouldn't be the first time. I just wish it would go faster! LOL It's still on warranty, piss-me-off. Any suggestions while on warranty to make driving more fun?

I'm in the same position. Mine is an extended warranty till 75k. That's a long time to wait for turbo, but time to save too. I found bigger wheels made mine handle a little bit better than the stok 14 inchers. Right now, just gotta go for audio and looks, and speed when the warranty is up.

hahahha so much pwnage going on here =]

in some cars......higher octane will actually hinder the car's performance (HP/TQ wise).....

when i still had my 2002 honda accord v6, it would only take 87......anything higher than 87 is a waste of money and a loss of power...

(i use to be specilized in my accord before i totalled it)

http://www.v6performance.net/forums/...295#post299295

my engine feels super smooth and pulls nice with 87.

listen, whether it's good or not. i've been using premium gas for a year now. ever since i bought my civic. it's kinda a habbit now to use that gas. i don't ever use anything lower than the highest gas. my car runs fine with that gas and it's probably better for it in the long run. makes me feel better to know or think about it. there's nothing wrong with using that high octane gas. it just breaks the wallet more. but then again, i NEVER let my gas gage get any lower than half a tank. i'm always usually filled to the max. cause i don't really go anywhere LOL. just work and back home.

I use diesel and teh car feels super smooth :rofl:

The mph can change if you pull off some bolt ons like header!! I took mine off and can go much faster at lower rpms because it was removed. Puting boosted gas in can change the speed some what!!! I have done this too and noticed a mph to rpm diff.

how is it that you guys are able to go over 4000 RPM?. i and see that some of you guys are reaching the 61/2 to almost 8 RPM range?....what the hell!?. you must be PUSHING THE HELL out of your civics.

Diesel...eh. Why don't you try a little diesel and coke before bed, get some good peaceful rest. Ha. I drive the sheet out of my car, it still doesn't go anywhere. Sounds like it should, but it don't. Fun to make noise.

I hope that was sarcasm, because 4k rpm is nothing. Thats cruising in 5th gear around 80 mph. 6 1/2k is gettin close to redline.

Anyway, i use 93 octane in mine, and i do notice a difference. It doesnt neccesarily go faster, but does run smoother since i installed my hi flo cat.

no that wasn't sarcasm. i guess i just don't push my car as hard as some of you do. i'm too afraid of blowing something. i don't think i've ever seen the RPM go any further than maybe 5000. but i don't watch it cause i don't wanna crash LOL.

i dont do it often, but its good to push it and make the motor work and clean out the carbon. ive pushed mine to 6k sometimes, you need to floor it and engage the vtec to get the oil flowing lol.

well yeah ofcourse. cause sometimes i'll do that and do bursts of 80 to 85 MPH and get good speeds and pulls. then the next day i drive my car. the gears work better and push into place much more better and smoother and the car doesn't jolt much (manual) and it just feels smoother and idles much more better. but i rarely push it. but ofcourse. i DO wake it up once in a while.

hey ashhole lol,
I noticed the same. Have you ever compared track times on say 87 and 93 octane? Wondered if there was much difference?

Rev limiter will protect the engine at 7000rpm on my car. 7000rpm sounds so good, man v-tec would be nice. Where are the 1.7L V-tecs rev limiters set?

ummm i wanna 7200, but not 100% sure. ive only tached it out once, and i was too busy trying to avoid the car i was cuttin off to pay attention to it