• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


Octane adjust Ratio

Messages
145
Likes
249
Location
Western NY
#1
Hey guys,
I have been running 93 octane with a 91 OTS tune from Cobb. I did this because I was worried that the 93 octane might not REALLY be 93 octane if you know what I mean. I figured I would err on the side of caution to be safe. For the heck of it, I re-tuned to 93 yesterday and after about 20 mins of driving the OAR gauge on the accessport went from -.74 to -1.00 (right where it should be). Do you guys think that this means it is safe to leave it like it is? Do you think the OAR gauge is a good way to make sure my octane or gas quality is sufficient for the 93 tune? Hope this is not a dumb question but maybe I am overly paranoid about this....Thank you!!
 


Jerickson88

Active member
Messages
720
Likes
204
Location
Rock Creek
#2
Hey guys,
I have been running 93 octane with a 91 OTS tune from Cobb. I did this because I was worried that the 93 octane might not REALLY be 93 octane if you know what I mean. I figured I would err on the side of caution to be safe. For the heck of it, I re-tuned to 93 yesterday and after about 20 mins of driving the OAR gauge on the accessport went from -.74 to -1.00 (right where it should be). Do you guys think that this means it is safe to leave it like it is? Do you think the OAR gauge is a good way to make sure my octane or gas quality is sufficient for the 93 tune? Hope this is not a dumb question but maybe I am overly paranoid about this....Thank you!!
I accidentally filled with 87 on a 93 tune, the OAR was severely diminished. I finished out the tank on the 93 time. Zero issues. If I'm not mistaken, the AP3 and car compensates for this.
 


XR650R

2000 Post Club
Premium Account
Messages
2,608
Likes
3,022
Location
Eerie
#3
This far east, you can count on 93 to be 93. You can't even find 91 where I live. Just go with a reputable top tier brand, and if the car seems to like it, keep using it.

I've driven mine on 91 out west, and 93 around here with my OTS tune, and it's a little punchier with the 93, for sure.
 


Jerickson88

Active member
Messages
720
Likes
204
Location
Rock Creek
#4
If remember correctly, one of the tech guys at Cobb told me that's the purpose of the OAR. To make adjustments for inaccuracy of octane and to keep your car safe. Aka fill up with 87 by mistake on a 93 tune and not be on the same timing curve and grenade your motor, kind of like a limp mode. It was a turd for sure. This was also in reference to e30 maps. Basically run e30 on 93 map until you're sure that you are at the e30, switch slots. Then if you fill with 93 afterwards, switch to 93 slot, as the e30 wont effect a 93 map.
 


Similar threads



Top