19bonestock88’s octane experimentation thread
 

So after hearing from multiple sources that Saturns tend to run better on 91-93 octane fuel than they do on 87 I decided to try it and do a little scientific testing to prove one way or the other if there is any benefit and perhaps get a feel for how much...

So far I’ve pumped almost 30 gallons of 93 into the car and have began instrumented testing, after which I’ll return to 87 and after a similar period for the PCM to potentially learn the difference, repeat the testing...

The original post below...
https://www.saturnforum.com/forum/sa...659/#post62033

And the pic of the timing curve that I logged and hand graphed
https://i1140.photobucket.com/albums...skmvdgjg1.jpeg

Any plans on getting and recording related obd data? The knock data would be very handy in the timing evaluation.

I so badly with I could record knock sensor data but I don’t have the capability to read it. I can see when it’ll occasionally retard timing after an upshift at low RPM so I think I can see it pull timing as it senses knock

So I also logged timing at various cruising speeds of 1k, 1.5k and 2k RPM, and had 24.5, 31, and 36 degrees respectively... it’s worth noting that 36 degrees is the maximum advance available at < 2500RPM...

I also noted that engine load at idle was pretty steady, going between 9.2 and 9.6% warm