SlowEJ8

iTrader: (1)

Just curious, but what octane, and what gas do you put on your car??
I tried googling the major and minor differences of higher octane rating, but i dont seem to get it, can someone explain?

Also if you view this, take some time and type in what gas, and octane rating you use, thanks!

98civdx

well for starters the highier octain the slower it burns, there for better mpg.
if you watch tv and see any of those gas comericals, and see all the addatives and what not, but preminm fuel will burn better there for better for the engine.

i run premium only 93 octian, bounch around bewteen 76 and shell.

RunninEg6

honda recommends the suggested octane rated for the vehicle. i used to put in 93. but since gas prices jacked up i settle for 87. the octane rating is just the resistance measure of fuel to detonation.

Many high-performance engines are designed to operate with a high maximum compression, demanding high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.

However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another.

civic_driver

The higher the octane rating, the less likely is the fuel to detonate/explode on its own (will detonate through spark only, which is how it should be). Generally, use higher octane gas if your engine has a high compression ratio. Using high octane gas in a lower performance engine won't affect its performance.

This has a good explanation: http://auto.howstuffworks.com/question90.htm

Btw, I use 87 which is the recommended gas for my engine (and I haven't done any performance mods to the engine).

civicvtec44

high octane fuel shouldn't be used on a stock N/a car will do nothing higher octane (premium)burns best at higher compression rate such as a in a turbo charged or supercharged car.. or a built N/a Car

smokey.23

i use 93 octane from shell, turbo on 10 psi

NightCat

Depends on what the gas prices are doing lol. I'm also at 7200ft elevation so the demands are different. 85 octane at altitude is equivalent to 87 at sealevel or some ****, so if its cheaper when I go to fill up i get the 87 octane midgrade. or if its stupid expensive I go with regular.

BryanM.

iTrader: (1)

Regular for my D16Y7 and premium for my B16A, because Honda says so.

IhateworkingoncaRs

I wouldn't waste the money on higher octane if your car calls for 87 and you have not done major modification to it. The reason for higher octane is that when you have a higher compression or you boost you are squeezing your mixture much tighter making it want to explode upon or before spark (flame travels extremely fast during explosions). Since most cars that I know of lite their mixtures BTDC(before top dead center), you don't want your flame to reach your piston until your piston has reached TDC and ready to move down. If it does, it is refer to as detonation. In fact, by running higher octane and not changing your electronic timing, your flame will reach your piston after TDC causing you to loose power. This is why tuners always mess with timing.

MonkeyMagic

**** ME, THATS SO WRONG I COULD SET AN ANIMAL SHELTER ON FIRE!!

the higher the octain the more resistant the fuel is to knock. (or to spontaneously ignite from heat or pressure)

high octane in an engine that doesn't require it will get you WORSE gas mileage.

additives are a completely different ***** house of chemicals which are either kerosene and detergent (aka fuel system cleaners) or just some bullshit chemicals (octane boosters) which will only raise one gallon of fuel .03 octane units. which really doesn't count because the gasoline's actual octane rating remains the same so in the right motor it'll still knock like the police.


i gotta smoke a cig, i'm getting cranky

RunninEg6

lol

IhateworkingoncaRs

Maybe if you don't smoke, you won't get so cranky?

I'm just joking don't yell at me.

civic_driver

MonkeyMagic

na, thats the problem, i'm quitting... ugghhhh

XKINGX

I run 93 on the street until boost comes in then a mix of methanol comes in.
on the high boost c16 and a higher mix of methanol

newtron63h

octane ratings. resistance to detonation(the air/fuel mix has been lit BTDC and the expanding gases start pushing down on the piston BEFORE top dead center so the piston is still going up, but the gases are trying to push it down....aka spark knock). the higher the number the more resistant(basically its more stable).

using higher octane fuel in a engine that has electronic ignition timing can POSSIBLY be beneficial.........depends on the programming of the system. higher octane makes it possible to light the air/fuel mixture earlier without the risk of detonation. if you can ignite it earlier then by the time the piston reaches TDC the gases will be expanding at a high rate JUST as the piston starts going down...........getting this series of events timed right is key to efficiency.

a common misconception is that the air/fuel mixture explodes in the combustion chamber, if this were true then we would be putting pistons in all the time.

in actuality the mix burns at a very steady, very predictable rate. this is how porsche is running 12:1 compression in the GT3 RS on 93 WITHOUT direct injection. its a very predictable burn as long as the right fuel is used.

Schister66

Use whatever is recommended. If you run higher octane, you're not going to see any gains in performance and mileage...you may actually see less mpg while paying more per gallon

SlowEJ8

iTrader: (1)

Jesus christ, most of the answers you guys posted are like wiki'd.
Any other opinions if running recommended octane is best for car/mileage, and obviously price?

Schister66

I can't speak for everyone, but my answers are my own. If you find that our answers are so simple, why weren't you more proactive about this. Search for yourself if you're going to criticize the help people give you.

newtron63h

wait a second, are you complaining about the information we are giving you? you asked a question. we are answering. if you dont want the information we are giving you(the only other information is wrong) the dont ask questions.

use the recommended, its what the car is designed for.

on a side note some cars have "MINIMUM" octane AND a "RECOMMENDED" octane. if this is the case then using the recommended will get you better performance, not mileage.

on a personal note, there is ALOT more energy in diesel than gasoline. everyone should read up on it and see how it compares. everyone compares miles per gallon. ever compared miles per dollar? just something to think about

RunninEg6

we give the most prominent answers to help each other out. i think all these posts have answered your question.

Schister66

x2

XKINGX

fellas I think he is saying the answer u are giving are over his head. I think not sure though.

RunninEg6

either way i think we all gave enough info

Unseen Racer

i used to use 92 octance.
but gas prices went up and unemployment sucks so i stick with regualr.
CHEVRON for the win!
or just read my sig