pain2bare

I've been filling with regular since I bought the car, while gas prices are low would it hurt to fill up on the higher octane?

imported_zhu

ya it'll hurt your walet

coreyhayman

running higher octane in a stock civic is just throwing your money away, your car doesnt need it or will it benefit from it.

TheModFather

only run what the manufacturer reccomends
itf your car is heavily modified IE FI or high compression then you can do it only tuned of course.

imported_viper_2_4

besides wasting money, I heard somewhere that prolonged use can clog your cat, not sure about that one though....

kimchee

Hmm... i don't know about that. I always thought higher octane burns more efficiently.

To the original poster: use whatever octane that is recommended in your manual.

91 is recommended for b16's

nashall

you get what you pay for.

imported_starboy869

Maybe you should read up on octane levels in fuel. Also read up on compression ratios.

The higher the octane # requires a higher temp. to burn.

imported_kIeRaN

i dont see it being bad to use it occasionally, but its really unessasary if ure driving a stock civic

imported_Thrill_House

I would only recommend using lets say "ultra 94" to help pass an emission test because of the higher alcohol content. Otherwise I dont recommend it for daily use unless you have a k20 or a modified engine such as mentioned by themodfather. Using higher octance gas in a car that is not designed to run it can leave deposits because it doesnt all get burned, and if you dont believe me then talk to Cynikal Mindset, there was a simalar discussion awile back about this and he had all the correct facts. Oh and on top of all that I have even talked to various people and Honda dealerships and Honda specialists and they all said unless you have a new Sir with the K20 then you should be running anywhere between 89 and 91 octance.

imported_2join performance

Octane, is a rating that tells you how much the fuel can be compressed before it spontaneously ignites.
If the fuel you use in your car doesn't have a high enough octane rating, you may experience pre-ignition or detonation. Pre-ignition occurs when the fuel/air mixture in a cylinder ignites before the spark plug fires. It can be caused by hot spots in the cylinder, red hot carbon deposits or extreme overheating. Detonation occurs when the flame-front in a cylinder does not proceed smoothly across the combustion chamber. The fuel may ignite spontaneously due to high compression or other sources of ignition. Pinging and knock are symptoms of pre-ignition or detonation and either of these can break piston rings and pistons.
If your engine runs without knocking or pinging on regular fuel, then you will have exactly the same power on premium fuel. The fuel required by your vehicle is shown in the owner's manual. Most vehicles need only regular gasoline but there are times when higher octane fuel is needed.

bruceTree

a civic will use so little gas, that it really doesn't matter in terms of cost.

$4 a week isn't exactly a drain on your wallet.

Cynikal.Mindset

it will end up being more due to carbon deposits which in time will make your fuel economy goto ****...you can end up losing 10-20% on your fuel economy not to mention loss of power due to using the higher octane that will never fully burn and gum up your valves, encrust your pistons and combustion chamber with carbon

BoneStock'88er

Try running 102 octane fuel with an octane booster in it, that will gain you like a extra 5 horse.

bbarbulo

iTrader: (2)

high octane just resists detonation better, no other reason

BoneStock'88er

I know lol I was just being stupid.

spazio10

If higher octane results in greater unburnt fuel with deposits, would that not be worse for an emmisions test?

TheModFather

the reason thrillhouse and i say run ultra 94 for etests is becasue it's really about 89 octane gasoline with about 10% of alcohol by volume! this way the octane ratings of the gas go to
89 motor octane
99 research octane
now when you average them out the octane rating is 94
here is the formula


research octane number + Motor octane number
....................................2

ron = 99
mon = 89

89+99
...2

=
94



the fact that the gasoline has such a large amoutn of alcohol (10%)
means there is efectively less gasoline and since the drive clean machine only picks up HC's, NO, CO and CO2 it does'nt notice the byproducts of the alcohol content!!! this is why for etests i always run ultra 94

hell my 1987 3.8T buick passed an etest LEGITEMATELY with a ****ed up catalitic covnertor and 94 octane gas, this car has more then 542 000km
and had 534 000 at the etest!!!!

spazio10

sweet cause i had a thread going about the HC's because i am due for an etest right now. been driving with a trip permit. i was looking for any info on how to make it easier to pass and this never came up in my thread. thanx The ModFather