Which came first, the gas or the tune?
 

When getting a CAI and a higher octane tune, should I let my tank get low and fill it up with the higher octane just before I install the CAI and retune it?

RE: Which came first, the gas or the tune?
 

You should run at least a tank of the higher octane your are getting a tune for before you upload it.

RE: Which came first, the gas or the tune?
 

Good thing I asked, I wasn't expecting that. TY.
I guess thats good cause I am getting antsy waiting for my stuff in the mail, but I can settle down since I will need to burn through some gas before I can install it anyways.

RE: Which came first, the gas or the tune?
 

Excellent advice. I ran two tanks just to be safe.

RE: Which came first, the gas or the tune?
 

I'm not sure what your mods are but if they're not to radical, I'd stick with a tune based on 87 octane. I had a CAI and ARH catted X system on when I dynoed at a hair under 300 RWHP on 87 octane. The tuner told me to come back with 93 octane in the tank so I went through a few tanks and returned. On 93 I got the exact same numbers on the dyno! He told me my car just wouldn't take timing so the 93 tune wasn't really doing anything for me. I'll never waste my money on high test gas unless I go with a power adder. Everyone can argue all they want but our cars run excellent on 87.

RE: Which came first, the gas or the tune?
 

I was wondering what the point of running a tank of the 93 octane through it before changing the tune? what exactly is helped that way? even if you have 1-2 gallons left and had 87 in, then put 91 in.. you have 2 at 87 and 14 at 91.. how much of a difference can it make?

RE: Which came first, the gas or the tune?
 

I figure if it worked for you guys then I'm gonna take your advice and run a tank of premium first.
But just out of curiosity, what exactly does this accomplish? I'm guessing it's about getting the newer gas into the fuel injectors and just the nitty gritty in general. Also, I know that with computers running just about everything on board, so maybe it adapts somewhat to the new gas. But then again I would imagine that retuning is going to override or perhaps refresh any of that data anyways.
Can't hurt though, and I'm gonna be waiting another 7-10 days to get my goodies from bamachips since I ordered the stuff on the weekend. Hopefully the shorter end of that time since the heart of dixie isn't too far from florida. Either way I think I can manage to burn through some gas before then. ;)

RE: Which came first, the gas or the tune?
 

It just runs the old, lower octane gas out of the lines and gets the premium gas all the way through.

I ran two tanks through mine before I loaded my tune.

And yes, with the FI, now the only thing I can run is 93.. Makes road trips challenging, but I manage.

RE: Which came first, the gas or the tune?
 

It will do nothing other than getting the 87 out of the lines that will be flushed through the system anyway. Once you flash the new tune you will have to run the car for at least 100 miles or 120 Km for the fuel trims to be learned and by that time you will have very little of the 87 in there anyway.

cheers

RE: Which came first, the gas or the tune?
 

Was it hotter when you dynoed with the 93 tune? According to Doug there is about a 10-12 RWHP difference between a 87 and 93 tune.