So...I was planning on running my 87 tune for the winter to save some $$$, but my gas milage really suffers. So I decided to go back to 93. I had my car down to '25 miles until empty' yesterday, and filled up with 93.

Do you think its safe to switch tunes now? Or should I run a full tank of 93 first?

Thanks!

 

Wait till you burn another 1/4, top it off with 93, then you should be fine.

 

I don't see an issue flashing back to 93 now, as long as you don't drive like a maniac at WO throttle.

 

Most likely your ECM can compensate for what would probably be a tank of about 92.6 octane. If you don't hear any detonation, you should be fine. If you can wait, I'd run it down some more just to be safe before going back to the 93 tune. What about going to 89 or a midtune in the meantime?

 

If it pings, buy some Klotz octane boost. If not, don't worry about it.

 

I think I'll flash 89 for a day or 2...then top her off.

Thanks guys!

 

I don't see a problem in doing it now

 

It probably won't matter, however if you want to be paranoid just wait til the next fillup.

 

on a side note
I too went to my 87 tune for winter, but the mileage was worse than my 93....
so I put some 93 in , preparing to switch back, but my 87 tune gets great mileage on 93 weird!

 

lol just posted same question