TNess

Not sure what I should use. The manual says 87 or higher. So is 89 gonna make a difference?

Newtmaker

Nope. Stick with the 87. It runs just fine.

Walt

UnFocused

87

BEASTXB

USE 87 FOR A WHILE THEN CHANGE TO 89 YOU'LL HEAR THE DIFFERENCE

squarepants

if the manual say 87 or higher 87 is what it will get,not to mention the price for a gallon of gas these days think i'll stick with 87....lol

dieselstation

everytimg this subject comes up.. a ton of people come on and give really bad or even false information. so i'd like to just squelch all of that before it happens.

HIGHER OCTANE GAS HAS ZERO PERFORMANCE BENEFITS. IT WILL NOT MAKE YOUR CAR FASTER, IT WILL NOT GIVE YOU MORE MPG, AND ALL YOU'RE DOING IS WASTING MONEY.

this information is directly from SHELL: http://www.shell.ca/code/motoring/en...es/octane.html

the ONLY thing that octane helps.. is to keep your car from knocking.

sexyscionlover

which is the problem ^

people see these high horsepower machines that HAVE to use high octane fuel to resist knock, and they believe they got the kinda numbers they did by changing fuel. i dont care who you are, if your engine isnt knocking then go with 87.

i personally just go with 89 because its cheaper in NE.


scott

jct

thats so true in my old car before i over heated i was running 87 octane and after i over heated blew a few casting/freeze plugs and blew a head gasket... had the heads milled ever so slightly and when i tried to put 87 octane in it knocked like a ****!!! no matter how hard i tried tuning it it still pinged on 87

so i had to put in 93 octane in a 23 gallon gas tank so yeah that was a lot of money just for gas at the time it was like around 40 bucks for a tank of gas every week!!!

lalagimp

resident idiot here; but what the heck is it like when an engine is knocking?
The only knock I've ever been around is when an old 83 dodge is running out of gas, and other than that i probably just didn't notice if it was because I don't know what to look for.

Scievolution85

I use 87, screw 89 when the gas prices are the way they are!!

boxboy

Well if you compare 87 89, the higher the octane the better the push your engine will do. It will not give you more power but lets say two cars are going up a hill, one is running 87 and the other is running 89..89 will go up easier and wont scream or push as hard as 87 . Yes 87 is cheaper, (by what, a couple cents?) but by the time it gets to the top of the hill, it will have burned more gas than the 89 did. The higher the octane the better lets say response it has when stepping on the gas. It may not be noticable but its definitely true.

Newtmaker

^^^^^^^ That may be true in So Ca with the crazy gas additives but my experience has been that anything beyong 87 is a waste. I can feel nor hear nor calculate no difference bewteen grades EXCEPT 10 cents per gallon price.

Walt

sexyscionlover

It just feels faster because your pockets are emptier



basically rule of thumb, go with what is cheapest as long as its 87 or over.

scott

Ericc

You will feel more power if...........
Your engine is knocking because the fuel grade is to low.

In my old GSX eclipse my cars timing would get pulled back and the boost would go down by about 5 psi when I was knocking. My car would even ping when I had 91 octane in it. So I would add some Xylene (About a 150 octane rating) to my gasoline. As soon as I did that I could tell my timing was being pushed forward and my boost gauge would read 5 more PSI.
The reason is because my ECU was retarding the timing and lowering the boost to keep my engine safe.
So yeah, higher octane will help if your car actually needs it.

jct

heres a few i tried too find a few sound clips of engine knock and came up emty

http://auto.howstuffworks.com/question90.htm

http://zhome.com/ZCMnL/PICS/detonation/detonation.html

you would know when its knocking cause you'll hear this ping ping ping ping ping pinging sound from your engine just as long as your not blasting your radio

it normaly happens when your engine is under load when your on the gas / going up hill

as we all know engine knock is very very very bad for engines

it sounds like a phone is ringing (ala with the two bells in the phone)

tclikewhaa

91 like whaa

R2D2

91 vs 89 makes a slight difference atleast on a 5spd...gives da car a lil more kick and makes da wallet a lot lighter

Tomas

The manufacturer says 87 works fine in your stock engine, so I would suggest using 87.

If you really know more about how your engine is engineered and what it needs than the manufacturer who designed and built it does, then please go ahead and use whatever you think best - be it Vitalis or 115 avgas.

R2D2

Whats the upsides and downsides of using 87-91?

tweetie

91 has better gas mileage... it runs richer...