93 oct on 91 oft ots tune

[AppleSauce]

My city got its first 93 oct pump in like decades and so i filled up woth it forgetting my tune is 91 from open flash tablet their off the shelf 91 stage 2 for headers. I remembered they have a 93 tune as well so I was planning on running a few tanks of 93 oct in it before i switch the tune to their 93 oct stage 2 tune. Is this okay? Do i need to wait a few tanks before switching it?
Also not sure if this is just the tune hut i also have noticed the AFR tends to run more rich (which i know os safer than lean) i see its almost always below 14.7:1 and especially now that its on the 93 oct which i thought would have the opposite affect.

[STV3]

Just drive normally until you burn through your first tank of 93 and you will be fine. Even if you go WOT the car might run a little rich, but you should be fine.

[mike7792]

correct me if I'm wrong, but I believe you can run a higher octane gas with a lower octane tune. You'll only have problems if you run a higher octane tune with a lower octane gas.

[sstfnv]

the OFT 91 and 93 are identical except the timing for high RPM so you are fine to run 93 gas with 91 tune.

[JB86'd]

If I were you I'd just keep running the 93 octane, it gives you a little insurance when driving hard or on hot days, you'll have less knock and probably better mpg too.

[phrosty]

You might get some knock at WOT if you use the 93 tune right away. Maybe run through a tank of 93 first. The power difference isn't even noticeable -- you need a dyno -- so you're not sacrificing anything if it's just your DD.

[Chimera]

I run my car on 93 oct, on a 91 tune all the time.

[AppleSauce]

The insides of my exhaust tips are atrociously black now

[steve99]

Originally Posted by AppleSauce

The insides of my exhaust tips are atrociously black now

The 91 you were using may have been an ethanol blend resulting is cleaner combustion, the 93 you switched to may be non ethanol hence the backer exhaust.

as @Wayno said the tunes are identical except for top end ignition timing over 5000 rpm.
oft tunes tend to be on the rich side which is safe

if you want a clean exhaust switch to e85 fuel and tune. :-)

[AppleSauce]

actually they were starting to get pretty dark before i put headers on and now they are just awful. next spring im getting SC and a real tune along with it so i will hopefully not have this problem afterwards