I've been trying to run out my tank of 87 in order to fill up with 93 and give the 93 perf. tune a try .

I'm finally below half a tank of 87 and will be taking a 250 mile round trip tomorrow, so that should do it.

Question is this: Can I fill up on 93 when I'm below 1/4 or do I need to wait until the low fuel light comes on?

Will it hurt anything to go to 93 tune with a bit of 87 gas mixed in there?

 

I'm not sure how long it takes you to switch tunes, but I'm assuming you're talking about an edge...

If it is simple to change back, then 1/4 shouldn't be a problem.. just pay attention to your engine.. if it starts knocking or feels funny, switch back to a lower-tune and burn off a bit more before refilling @ 87.

The higher the octane the more air can be added since higher octane fuels are more stable and less prone to pre-ignition or "detonating" due to compression friction (like how diesels run)

You could always try getting a octane booster...

also, after filling up.. drive for a little bit to use the fuel in your lines before switching to your higher setting.

 

Hi Tex - wait until the low fuel light !!!!

1/4 tank dilution is far too much - it's a true 93 octane custom tune, NOT a 91+ octane tune like the canned Edge .... which means it's predicated upon having high quality, full 93 octane fuel in that tank. It will pull timing on anything less.

And unless you have access to Torco, NEVER add octane booster - it's crap, ineffective, and can contaminate your O2's.

So - say you already went and did this - well you do have the ability to remove spark in your Xcal2 - if you need to...

And - WTF is with posting a question like this just prior to leaving? No time to see enough answers - hope you see this before yer gone Safe trip!


bubba

 

Hey Bubba, thanks for the info!.. I actually summoned the brain cells to check on here right before I walked out the door, and glad I did!!

I went ahead and pumped enough 87 to get me there and back, so now I'm about back where I was.. I'll run 'er down to the low fuel light this week before filling up on 93.

And just as an aside, the freakin' passing on little two lane highways is soooo easy now!! Holy Crap!! I'm sure I scared the hell outta a couple of deer hunters - today was opening day - but I sure can pass now in places I wouldn't have attempted before the tune..

Anyway, sometime about Wednesday or so I should get the low fuel indicator.. I'll switch to the 93 perf. then and probably never look back..

 

Also remember your fuel line is still full of the old octane.

 

Well yes.. but I aint gonna run the ****er dry before I fill up.. LOL..

Hey, if a gallon or 4 will hurt on a 30 gallon tank then I might as well not even try..

 

OK, ran it down to the "low fuel light".. just in time for 93 to go to $3.12.. LOL

So $90 later I was filled up with 93, changed the tune and got about 10 miles with the 93 perf tune..

Biggest difference I noticed from the 87 perf is the the shifts are firmer.. And that under a tiny bit of WOT it squealed the tires at the 1-2 shift!!

10 miles isn't enough to say anything, but... damn

 

Belt slip!

 

so when switching from 87 to 93, or 93 to 87 you should run as low as possible, fill up full and drive for a few miles to clear the lines of old gas? Just asking because i have XCII on order and always wondered about this

 

It's crucial for the 87-93 switch only. Yer good to go when you refill after hitting the low fuel warning.

 

Why not just drain and/or siphon out the gas tank?

 

^^^ Cause that is totally unnessecary.

When the low fuel light come on you have about 5gal left. You should assume worst case you are gonna get at least 10MPG. Therefore before switching from 87-93 you should drive atleast 50 miles after the light comes on before filling up. The switch back from 93-87 doesnt matter. you could run 93 all day on an 87 tune and the only thing you will hurt is your pocket

 

I would almost garuntee not nearly as many people would buy multiple tunes if they had to drain or siphon the gas out of the tank to change tunes-i know i wouldnt

 

Okay, been on the 93 perf for a few days now and I'm very impressed!!

The 87 perf. made me think I had a different engine and tranny, so I couldn't wait to try the 93..

If anything the shifts feel even quicker and overall the impression is that there's just more power..

And no Suzuki, it aint belt squeal... LOL

Kinda trips me out a little, but yeah, when I'm rolling in 1st and then floor it it breaks the damn wheels loose for just enough to squeal 'em when it hits 2nd..

 

I have been holding off on making the switch to the 92 octane tune (out here in Hawaii 92 octane is the highest they got). Well my tank is getting pretty low (well below 1/4 tank right now) and I'm getting my 4.56 gears installed tomorrow. Once I get my truck back the first tank I fill up with will be 92. Hope it's as good as it sounds.