Ok, so I know 93 octane is best for my new princess and that's all I'm giving her to drink.

But, I can't guarantee the sales guy filled her up with premium. I know that if he didn't and regular unleaded was used, she would retard timing and other things.

But, my quesiton is, does that self correct once premium is being used again. I have only used premium since i purchased her, but of course it was a full tank of unknown gas when I purchased.

Any responses?

 

Poor princess...She got a bad case of GAS......

 

nice

 

I found this article out there. I think I may try this. Anyone have a reason I shouldn't, other than "at your own risk"?
Underperforming L99 engine Camaros : problem, diagnosis, and cure | 2011 2012 Camaro ZL1 SS LT Camaro forums, news, blog, reviews, wallpapers, pricing - Camaro5.com » Blog Archive

"at your own risk" always makes the hair on the back of my neck stand up. Anyway, here's a short excerpt from the article.

"
So, if you suspect that your L99 based Camaro may be underperforming due to past low octane gas, what can you do? You can try to pull certain fuses from the fuse panel which will result in a reset of the computer’s memory, thereby allowing it to attempt to re-adapt to running at a higher octane level. Instructions and photos of the process can be found HERE. Please note however, that neither Camaro5 nor GM officially endorse this DIY fix and taking such actions and its consequences will be at the owner’s own risk."

 

So if I read that correctly, the computer in your car "holds" the timing information based on the octane you're using, and it could get "stuck" there? Wow! Other systems I'm used to would continuously adjust the engine's timing "on the fly", based on the feedback the computer would get from the knock sensor in the block. The amount an engine is likely to knock depends upon the fuel, as well as the load that's being put on the engine. So, if using lower than required octane gas, with the car loafing along, the timing could be more advanced. Stomp on the gas pedal to put a load on the engine, and the k.s. can cause the computer to retard the timing. Ignition timing is ever-changing as you drive. But, that article suggests your system "locks" the timing in? Doesn't make sense to me for it to work that way, and it's counter-productive to achieving optimum timing at all times (which is what you want). I would just put premium back in the next fill up and see how it goes.

 

I've put nothing but premium in it since i bought it. There were 44 miles and a full tank of gas when I purchased it. I have no idea what kind of gas was in there. I am by no means an auto techie, but reading the some of the comments, someone stated that gm goofed and once the tables were set for lower octane, they do not automatically readjust for higher octane... but what do I know?

 

i'll give it shot..I don't think it'll hurt anything. Unless it's really dramatic, any perfomance difference will be strictly subjective.

 

Ok here is my report.
I think it made a difference.
I've had two vettes, one being a ZO6, so I feel somewhat qualified to comment on the performance of my princess.

I know a camaro isn't a vette (they are two different breeds) but my 2011 2SS A6 has more bhp than my 2001 ZO6 and I never questioned the performance of my ZO6.

They day I bought the car I let my girlfiend drive it and she made a comment that I just tossed aside as "ah, it's a new car and you aren't used to performance cars, you're a woman, what do you know?" hmmmm.. maybe she knows more than I thought. But as I have driven the car, I kind of have the same feeling.

Obviously the procedure is very simple. Pull a couple of fuses, wait several hours, (I'm not sure why but I suspect the eprom of the computer has a backup capacitor for charge and that needs to fully drain for the reset to occur), replace the two fuses and drive off.

Observations:
1. Start up and idle seemed much smoother ( it seemed that start up, and going into idle mode, there was some soft of "miss" or something.

2. Idle is definately more refined. Previously at stoplights and such, there was a noticable shake in the car. I was trying to convince myself this is normal for a car with this much power, but my ZO6 didn't do that.

3. She seems more eager to go now than before. Previously, especially at lower rpm's when applying gas, there seemed to be a "miss" again that word... I'm not sure how to describe it. That seems to be reduced, or gone.

4. Hard to tell, but when the need for speed arises, she jumps right into the game.

Like I said, these are subjective observations. I don't have the equipment to hook up and read the tables, so I don't know what may have happened inside the computer. Besides, if I had the gear, I wouldn't even know what I'm looking at.

It would be interesting if someone that has the gear, and the knowledge to investigate this and report back to the forum.

 

Plug a scanner in and it will show the spark timing as you drive around.

 

It should have premium all the time and as far as that article goes, I am not too sure about the Camaro ECUs but I know that on mine, it self adjusts. But I use nothing but premium because Im blown from the factory....