Murderjetz

I'm in the process of buying a 2006 Civic DX-G Coupe. Test drove it yesterday, and the guy recommended that I use 90 octane fuel, that it's good for this car. I'm confused because gas stations here sell 87, 89 and 91. and also the Honda website recommends regular (87).

I'm not even talking about gas mileage, I'm wondering, does it make a difference in terms of how good it is for the car?

also a buddy of mine once said "I think everyone should use premium. it's so much better for your vehicle".

wheelspinLX

If your manual recommends 87 octane then use that. There is no benefit to a higher octane, its only more MTBE running through your engine and gunking it up (not to mention wasted $).
Also its probably been covered before so always use the seach function.

HondaCivicCat

iTrader: (4)

Hope this helps,

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more. (more info found here)

Unless you have a higher compression engine than normal or are running really high revs all the time (I mean all then time). Or if the factory recommends higher octane (like the Si's) then 87 is fine. The stigma that your car drives better the higher octane gas you put in it is not true) If you engine does not knock on regular then its doing the same thing as higher octane gas.

Anyone feel free to correct me if I am wrong.
Cheers

gearbox

iTrader: (95)

natural gas engines do have higher compression i believe, so using a higher octane is better on the motor. if it says 90, use 91. oh wait a minute, youre in canada. is it just a regular civic dx? whats the G for. if its regular civic, and manual says 87, use that.

Murderjetz

Thanks, guys. I think that makes sense...

as for the DX-G thing, I think it's just a DX but with a few extra things, like 15" lightweight alluminum-alloy wheels and Electric variable power-assisted rack-and-pinion steering, remote entry, stuff like that. Turns out there are 4 trim levels available in Canada rather than just 3.

wheelspinLX

The natural gas civic is GX i believe and i think they only sold in california, may be wrong though. I also think its impossible to run gasoline in those.

DsevenEm2

iTrader: (6)

use whatever the manual tells you.. you can use more.. i use 89 or 93 just because i think i get more mileage out of it.. not sure if thats true or not but thats what it seems like.. gas last longer when its 93 compared to 87..

phuviano

iTrader: (5)

Just use reg. 87 octane. Your wasting money on any other octane level.

lordhelmet

iTrader: (3)

125 octane. I'm a salesman and I know you need 125 octane.

drunkenmagnum

iTrader: (5)

87, Your wasting money otherwise.

kcari

iTrader: (5)

i've used 87 and my acceleration was crap compared to 89. so i always use 89

beadebaserr

iTrader: (7)

it was all in your mind man.

there is no reason to put anything other than 87 octane in a d17.

kcari

iTrader: (5)

im pretty sure theres a difference, i've tried it a couple of times thinking its just my mind, but i really notice the difference...

MisterFrankieJ

iTrader: (2)

yea.....science > your butt dyno

HondaCivicCat post pretty much summed it up.

DsevenEm2

iTrader: (6)

even though it doesnt get petter performance from an engine.. which i know it doesnt.. would that mean the MPG wouldnt change??

Im almost positive that my gas lasts longer with 93 than it does with 87.. im about 99% sure theres a huge difference..

is that all in my mind too??

phuviano

iTrader: (5)

Yes its in your mind.

civicninitwo

Simple run 89 for non-VTEC. ALL VTEC run 93. Look on the god dam (sorry my tourette's) I mean look on the gauge cluster, any factory VTEC equipped acura/honda it says premium fuel only ON THE GAUGE CLUSTER. They aren't doing it to take your money. Your talking what 10 cents more a gallon? That's a couple bucks per fill up. Save out on the AMP energy drink and give your baby what it needs.

Plain and simple, better gas makes better power. It burns much cleaner,and results in much longer injector and O2 sensor life. One way or another you'll end up spending that loot. Easier than replacing parts.

One odd thing I have found is that in non-VTEC motors 93 octane runs great, good power, but you do not get the fuel economy like with 89 (mid). Odd I must say, but I have multiple civic's & crx's SOHC's and DOHC's vtec and nonvtec,94 integra GSR,and 95 prelude SE.

I have tested this rigorously and documented my miles.

It's no joke. It just works.

Peace, B

mgsjester

civicninitwo...You are probably the dumbest person I have ever known in my whole entire life.

phuviano

iTrader: (5)

ditto.

rice4lyfe

iTrader: (9)

yea, that guy's dumb.

use your reccomended gas octane. There is no advantage of running 90 gas in your tank. The only reason you would want to run a high octane is to prevent the gas from igniting, thus needing a higher octane to prevent knocks (preignition). If you are running turbo, or changed the timing on your vehicle, then you would want to run a higher octane.
But running your car under 93 octane once in a while to clean the carbon off your engine is fine. I do it once in a while, I can tell the mileage on the car increases.
On the other hand, you don't want to run any higher octane all the time either. Pioneer (or whatever other company that sells 94+ octane) just adds alchohol content to the gas, to raise the octane. This not only is useless for our cars, but it also destroys the fuel pump/system.

Thats the information I recieved in school, and is also my opinion, any re-butt-tuls(sp...i cant spell for ****.lol)

Murderjetz

I don't really get how using 93 once in a while would clean up the carbon build up. I use Seafoam for that.

wheelspinLX

People really dont understand how higher octane gas works at all lol. Alcohol raises octane rating negligibly but they are only allowed to add so much depending on the time of the year. Methyl Tertiary Butyl Ether is the real octane raiser and its notorious for creating carbon build up. That is why premium fuel needs a lot more detergents.

Randolph Jones

your saying to people to use nascar racing fuel or jet fuel in the peoples street driven cars LET ME SAY TO YOU THIS YOUR F@#KING CRAZY TELLING PEOPLE TO BE PUTTING 125 OCTANE IN THEIR CARS SO THAT ALLS THAT WILL YES IT WILL MELT YOUR PISTONS AND YOUR MOTOR AND YOUR MOTOR WILL EXPLODE SO DONT NO BODY DARE LISTEN TO THIS PERSON THATS TELLING YOU TO USE 125 RACING FUEL OCTANE YOUR CAR MOTORS ARE MADE OF ALUMINUM HEADS AND PISTONS AND MOTOR BLOCK AND AS SOON AS YOU GO TO THE RACE TRACK AND TRY TO BUY 125 RACING FUEL OCTAINE THE RACE TRACK WILL NOT SELL TO THE PUBLIC AT ALL BECAUSE RACING FUEL 125 OCTAINE FUEL HAS TO BE ADDED INTO THE CARS FUEL CELL NOT NO GAS TANK AT ALL RACING FUEL IS HIGHLY VERY DANGEROUS AND CANT BE PLAYED WITH AT ALL THATS WHY YOU CANT GO OUT AND BUY THIS 125 OCTAINE RACING FUEL BECAUSE SOON AS YOU START YOUR CAR UP WITH THIS KIND OF FUEL BEING IN YOUR CAR YOUR CARS GAS TANK AND YOU AND YOUR CAR WILL EXPLODE AND BURN TO DEATH INSIDE YOUR CAR EXPLOTION AND THE FLAMES HEAT IS HIGHLY SO INTENSE IT HAS TO BE PUT OUT BY BEING SPRAYED DOWN BY LOTS OF FOAM LIKE THEY DO AT NASCAR RACE CARS THAT ARE ON FIRE REALLY BIG HUGE FLAMES SO NEVER TRY THIS KIND OF HIGHLY DANGEROUS DEADLY FUEL IN YOUR OWN PERSONAL EVERYDAY DRIVEN STREET CARS AT ALL TRUST ME FOLKS ME AND MY FAMILY RACE SUPERSPORT NASCARS AND THATS WHAT WE HAVE TO IN OUR NASCARS OWN FUEL CELLS AND OUR RACING MOTORS ARE BUILT FOR THIS TYPE OF FUEL AND WE ARE CERTIFIED AND TRAINED TO WORK WITH THIS TYPE OF FUEL THATS ONLY FOR NASCAR RACING AND DRAG RACING ON DRAGSTRIPS FOR DRAG RACING

FRSam

12 years later, and we've had no reports of cars exploding or pistons melting. Safe to say that 125 octane is safe in our daily cars.

xRiCeBoYx

iTrader: (22)

Also, people putting in race fuel or some sort of alcohol injection typically have built their engines. I ran 110 in my turbo D17A2 and didn't melt a single piston. Engine didn't blow up either.

FRSam

No way, 125 on stock car only or you’re doing it wrong.

xRiCeBoYx

iTrader: (22)