How much better is 93 octane vs 91 octane

[aernan]

In California we have only 91 octane available :mad: . At a local station I can get 100 octane. Will the ECU detect the change in fuel if I run a single tank?

In states where you can buy 93 is it obviously better?

[Sponsor]

[lddavis]

A tuner (you can guess which one :)) on another forum was kind enough to post their results from baselining the stock tune with 87 and 93 octane. It's not exactly what you asked, but you can imagine 91 splits the difference.



I don't know whether the ECU can advance the timing enough to make 100 worthwhile. It will adjust to whatever you put in the car, but it does have hard bounds.

[aernan]

sorry the image is missing.

[lddavis]

Hm. Works for me, but probably only because I'm registered on that forum. I've copied the image to another place on the web which should be publically viewable. Let me know if it still doesn't work.

[aernan]

yeah that works. Thanks.

[bigdesignmachine]

I have been running 93 octane ever since the first tank of gas the dealership filled me up with. I believe I was using 83 prior to 93 but I may have that octane rating wrong. I didnt see much of a gain in MPG....I would say perhaps 1 - 3 MPG on avg depending on my driving and the weather.