I've been studying Hydrocarbons for a few weeks in Chemistry class, and my mind wondered what was difference in octane levels. All I know is that it’s C8H18.

 

The "octane" rating of a fuel has little to do with "octane" the hydrocarbon, it's a measurement of how well the fuel resists detonation when compared to pure octane (which supposedly has an octane rating of 100).

The reason that higher octane gas costs more is because people will pay more for it. It used to be that premium gas contained more detergents and additives than regular, but they're pretty much all the same now, except for a few additives to increase octane rating that get added at the pump.

 

I could not agree more. they only reason 93-94 octane gas costs more is because you'll pay the price.

The difference in refining cost is nil.
Its all in the marketing. Just like little cans of miracle octane booster, oil additives, gas savers.

 

So I'm paying 1.75 a gallon for 93 Octane because I'm a sucker? Great....

 

 

Yea, that sucks man. I need 93 or it'll start knocking

 

And the octane boosters are the biggest crock of all... Motor Trend or one of those car magazines did a study a few years back, and found that on average, octane boosters add between .1 and 1 "points". At anywhere from $3- $10 per bottle, thats a major ripoff imo.

 

If you really want to increase the octane rating of your fuel, add some tetraethyl lead. Of course then you can kiss your oxygen sensor, catalytic converter, brain cells, and the environment goodbye.

 

theres also a bunch of other cheaper, easier to obtain chemicals that you can buy and mix into your tank to raise the octane rating...

 

ya..ya... but where can you get those other additives like the lead or whatever whatever you said, rofl...

w/ lead... can't you run higher compression as well?

i remember my father 30-40 years ago ran 12 compression on his motor... 69 camaro ss he built himself... unfortunantly, i wasn't thought of then, :'( .. but.. he said he never had problems... but couldn't keep it up cuz no more lead....

what about those "OCTANE BOOSTER!"s.. that they sell at autozone? rofl... i doubt they work.. or that NOS bottle fuel booster thing.. they do ANYTHING at all? or close to nothing, & not worth the trouble?

 

Lead was used both to raise the octane (which was around 104 or so with premium back in the day) and lubricate the valves too. Thats why when leaded gas went away, engines started getting hardened valve seats. They needed hardened valve seats because there was no more lead to lubricate the valves, so they would get eaten away in no time.

 

iditiotic non lead gas lovers.. pfft. kill the seals why don't you... just kill em

 

You guys are only paying $1.75 for 93 octane in NJ?! Out here in Cali it's $2.03 - for 87 octane! I guess I'm the sucker. I think it's time to move.

 

mmm, sux man...

i'm only paying about 1.80 here in fl.. it changes within 2-3 cents either way about every week. :-/

 

That is exactly what I was going to say!!! You guys are complaining about paying 1.75 for 93, you ungrateful bastards. I would be happy to pay that for regular!!! We can't even get over 91 octane and that is like 2.20 or 2.30. Anything more than 91 can only be got at 76 and that is like 4.00 or more PER GALLON. OMG!!!! We are getting screwed here in california. They really have us bent over with our pants down.

 

i just paid $2.43 a gallon for 91 octane, I LOVE CA!!!!!!!!!!

 

The only real difference is the additional additaves they put in it to slow the burn and prevent detonation. I think the base might be a higher grade as well. Awhile back I asked my dad, who, among other things, is a chemist, and he wentoff on a little tangent about how it all works. I was just like 'zzzzzzzzz.....' so i dont remember much of what he said. Maybe Ill ask again.

Ouch, almost 3 dollars for premium? Why not jsut run regular ol' unleaded? Im glad its only a dollar sixty something here in NJ. The more I tune my car, the worse the fuel economy is. Im lucky if I can get 16 - 18 mph lateley.

 

lastnights news story... gas prices are "record highs"

thats right.. here in mount pleasant, SC, it hit 1.63 or somthing like that, with it projected to possibly hit 1.80 during the summer..
then again, i go out of mount pleasant to fill the tank and only pay 1.49 a gal.. on avg, its 10 cents cheaper in north charleston... nice drive too.



just like the guys in cali to pull other guys pants down eh?....
is it any wonder why i dont even want to visit the state?!

 

yeah, up here Oregon, things are not much better than in cali, we are in the 1.89 range for 87, and over 2 for 92 (the highest we can get in this stupid, hippie run, evro-**** state) and on top of that, we can't even pump our own gas

 

More like you pay that because everyone is a sucker and don't really know what they're getting. Nor do they know what they're doing, their manual says use no less than 89 or whatever, so they figure higher is better. Never mind the gas that's wasted.

Across the harbor I pay $1.98 for 91. Even out on Long Island which used to be a good deal cheaper, I paid a whooping 3 cents less yesturday. Used to be at least 10c. And that's self service.

On the news a while ago they had a story about Jersey raising prices on the NJ Turnpike because they were sick of NYers coming over for the cheap gas. DOn't know if that's true or there were other reasons, but that's what was reported.

 

Someone told me all carbarated engines should use 93 octane. They sai it will burn better with less carbon build up. I have been using 87 without problem. Should i change over because of the carbarator?

 

We may only pay $1.50 for base gas but consider $400/mo insurance for a 20 year old Corolla cheap

 

I gotta disagree. I have an '88 Dodge Daytona (turbo 4-banger) and when I run regular gas in it, the engine can only hit about 10 psi boost before it starts to detonate.

With premium, I can turn up the boost to 18 psi and there is no detonation.

FWIW....

 

umm, yes it has higher octane... you just stated a perfect example of a motor to use higher octane gas with...


but that has nothing to do with why they set the price of higher octane gas where it is.

 

U R right. Sorry, I quickly read throught the posts and missed some of the meaning. Nobody was doubting the increase of octane, just the costs.

 

If your car runs fine on lower octaine fuel theres no reason you need higher octaine it doesent benefit the engine one bit. Some newer cars will alter the fuel map and ign timing when you add higher octaine fuel but not on a 3rdgen. Too bad all my stuff needs the extra resistance to detonation, I dont much like having my base timing set at 5* @ 5000ft to keep them from rattling on 85 octaine, rattling too much that is. Just gassed up the truck 10 minutes before they raised the price by 3 cents today. 85 $1.59.99, 87 $1.69.99 and whooohoo 91, $1.79.99. 43 cents of that is tax.

 

You Cali guys know how much of that is tax? From what I understand you guys pay alot more tax on fuel because of all the constant mind numbing road construction.

 

According to the parts in your sig, you actually don't need 93 octane!

In my opinion, you either have the timing advanced too far or your cylinders are carboned up.

You should be able to run 87 octane no sweat.