What type of octane I should use???

[krakkhenz]

Im a little confused about this, my car seller told me that I should use 95 octane gas, but the manual says I should use 91

What are the difference between 91 and 95???

My yaris got a 1.3 engine.

[why?]

I'd go with what the manual says.

The difference between octanes is how much pressure is required to ignite the fuel. The higher the rating the harder it is to ignite the fuel.

[GabL]

I thought the car (Yaris) can run on 87?

[why?]

Originally Posted by GabL

I thought the car (Yaris) can run on 87?

The rest of the world measures octane differently then we do in North America.

[GabL]

oh, didn't saw the OP was from Panama...

[as400g33k]

the yaris is rated to run at 91 but can also accept higher octane. most people would claim a performance boost when using higher octane. while some would even claim better fuel efficiency with higher octane.

we use 91, as it is cheaper than 95, 98 or 100 octane. :)

[GabL]

Originally Posted by as400g33k

the yaris is rated to run at 91 but can also accept higher octane. most people would claim a performance boost when using higher octane. while some would even claim better fuel efficiency with higher octane.

we use 91, as it is cheaper than 95, 98 or 100 octane. :)

100 octane!! It's gonna burn like

[swng]

Don't worry friend, the higher is the octane no., the harder it is for the fuel to burn.

[ToTo]

Hi guys! So the harder for the fuel to burn is not good in the long run? I have a TS model, I currently use 95 octane... What if I were to use 98 or 100 octane fuel, what would change? Would the car run better or would I feel a bit more power or torque, or is all this just BS?

[GabL]

Use what is recommanded in your user manual...

http://autorepair.about.com/od/engin...hoctanegas.htm

[swng]

Originally Posted by GabL

Use what is recommanded in your user manual...

http://autorepair.about.com/od/engin...hoctanegas.htm

Actually, you and why? know a lot!

[swng]

Originally Posted by GabL

Use what is recommanded in your user manual...

http://autorepair.about.com/od/engin...hoctanegas.htm

I refer to my previous post and the link recommended by Gabl above(Thanks Gabl!).
I am not here to convince anyone to use higher octane fuel on old and not so well maintained cars(NB: more old than new cars are not too well maintained because of lack of warranty and regular attention or willingness of the owners to invest further money in them; lots of exceptions exist though). I do not think I ever can.
Yet, I wish to point out that I have based my comments on the paragraph under "Should You Ever Switch to A Higher Octane Gasoline?" of the linked article. Obviously, the writer thinks it is o.k. to try using higher octane fuel first when knocking is detected on a car (on which the user's manual recommended grade of fuel is already in use). If the problem persists, then he reommends to have the car repaired or tuned up, which is utterly logical.

[why?]

Originally Posted by ToTo

Hi guys! So the harder for the fuel to burn is not good in the long run? I have a TS model, I currently use 95 octane... What if I were to use 98 or 100 octane fuel, what would change? Would the car run better or would I feel a bit more power or torque, or is all this just BS?

Unless you are experiencing rough running or misfires, then odds are the car would not run smoother.

However there prolly would be a slight increase in tourque and fuel mileage with higher octane fuel.

With fuel that is harder to burn, the spark timing can be set better, and the detonation can be more exact. This also means that the computer can use a more exact air/fuel ratio.

The thing is if your vehicle is stock, it might not make a difference that you could actually feel in everyday driving. The only way you could tell is by using a dyno, and that gets really expensive.

[wwwh355]

Originally Posted by why?

Unless you are experiencing rough running or misfires, then odds are the car would not run smoother.

In case of misfires, I thought u should get lower octane rated fuel which is "easier" to fire.

[AutoTech1]

Originally Posted by ToTo

Hi guys! So the harder for the fuel to burn is not good in the long run? I have a TS model, I currently use 95 octane... What if I were to use 98 or 100 octane fuel, what would change? Would the car run better or would I feel a bit more power or torque, or is all this just BS?

You don't need higher octane, unless you are running some set up that requires it. You are wasting your money on protection you don't need.

[ToTo]

Originally Posted by AutoTech1

You don't need higher octane, unless you are running some set up that requires it. You are wasting your money on protection you don't need.

I was just curious cause many people have this issue, whether the car runs better or not, or is it better at all for the engine and such?

[AutoTech1]

Originally Posted by ToTo

I was just curious cause many people have this issue, whether the car runs better or not, or is it better at all for the engine and such?

The car has no performance gains and it doesn't do anything more than what your recommended octane does. Octane is choosen to resist detonation. Here is a link that explains more of what I was trying get at as well as why?: http://www.geocities.com/runyardj/OctaneExplanation.htm

[why?]

Originally Posted by AutoTech1

The car has no performance gains and it doesn't do anything more than what your recommended octane does. Octane is choosen to resist detonation. Here is a link that explains more of what I was trying get at as well as why?: http://www.geocities.com/runyardj/OctaneExplanation.htm

I disagree with that statement. I believe using a higher octane might get better gas mileage and a little better performance.

I believe this because all manufacturers use 93 octane in the USA for all the testing.