What octane gas do you use?

[GM991]

Hi all
was wondering what everyone runs in there cars on the street for octane gas?
I run 93. What does the factory say?
Do you think there is a big difference between 93-89 Performance wise?
The cost between the two can be as much as 20 cents a gallon.

thanks
Gary

 

['13_ImpactBlue_GT]

I run 87.

 

[StratGT]

If your car is not knocking with 87 octane, then you don't need anything higher. Higher octane will not give u better performance unless you bump up your timing. It's a waste of money.

I have a steeda timing adjuster set at 12.5 degrees and use 87 octane and had no pinging. It pinged at 14 so I lowered it to 12 1/2 and it doesn't ping. Maybe we have better gas here in Canada, or maybe our weather just sucks cause our last summer was cold. There was no difference when using a higher octane in my car.

 

[JonJon]

87.

 

[2K Stanger]

I run 91

 

[Firemanz]

Must run 93......

 

[Gearbanger 101]

87 now...93 after blower install.

 

[Marks5.0!]

93 octane

 

[rjstaaf]

The reason for higher octane is to prevent detonation by more resistance to spark. Higher octane gas is harder to ignite and hence if your car doesn't require it, likely you aren't fully burning it. Higher octane gas is purely to prevent detonation, it does nothing for performance.

 

[donsbad68]

87 on my stocker

 

[Silvr04GT]

Exactly there is NO reason to pay more for gas than you need to. If you have a stock or stock car with bolt ons that don't affect timing just run 87, anything else is a waste.

Get an SCT chip and bump the timing then pay the extra for the good stuff. No point in spending money you don't have to, you could use it for more mods!

 

[aggiedj02]

87

 

[GM991]

I always thought higher octane fuel burned cleaner and gave you better gas milage....

 

[rjstaaf]

I always thought higher octane fuel burned cleaner and gave you better gas milage....

Oil company propaganda. Shows you just how effective advertising is huh

 

[Gearbanger 101]

I always thought higher octane fuel burned cleaner and gave you better gas milage....

No, quite the oposite, actually. The higher octane fuel burns slower, which actually creates more emmisions. The only way it give you better mileage is if you've got the timing advance far enough to take advantage of it. Otherwise.....it's money down the drain.

 

[Slapyo]

i run 91 octane and have a timing adjuster at 16 degrees ... no pinging.

 

[GM991]

Are there are knock sensors on our cars?
If so
On modern engines with knock sensors, higher octane fuel may make the engine run better if the knock sensors are retarding the ignition timing, which hinders performance??????????.....

 

[rjstaaf]

There are knock sensors on our cars right? If so
On modern engines with knock sensors, higher octane fuel may make the engine run better if the knock sensors are retarding the ignition timing, which hinders performance??????????.....

Huh, not sure I follow this?

If you are running 87 and you get pinging(detonation) then yes, running a higher octane will help. If your car is stock, the manual calls for 87 and you are getting pinging with 87 than you have a problem and running a higher octane fuel isn't going to fix it. You should always run the lowest octane possible, preferably what your owner's manual calls for unless you have mods that require a higher octane.

 

[Kilgore Trout]

I think only the newer 4Vs have knock sensors. I do not think any 2Vs have it...

 

[GM991]

Huh, not sure I follow this?

If you are running 87 and you get pinging(detonation) then yes, running a higher octane will help. If your car is stock, the manual calls for 87 and you are getting pinging with 87 than you have a problem and running a higher octane fuel isn't going to fix it. You should always run the lowest octane possible, preferably what your owner's manual calls for unless you have mods that require a higher octane.

If our cars have knock sensors. The computer will change the timing so the car will not knock with the lower octane gas and that would change the performance of the car.....