I'm about to purchase a STi soon and have been following the discussions about the ping/detonation. Being in CA, we only get 91 octane and some 100 octane at a few select gas stations. I forgot where I read it (somewhere in this forum), but it suggested to sticking to only one kind of gas for best performance due to the different additives that are in each brand of gas (such as 76, Cheveron, etc.). Is there any truth or benefit to sticking to just one kind?? Are any considered to be better than others for one reason or another?

I think you could also make a very good argument for rotating gasolines say... every month.

The additives in one brand are better at dissolving certain types of junk in your fuel system, while another brand is better at others.

I saw this recommendation in an article about how gasoline is made.

Interesting point KoneKiller. Where did you see this article? Anyone else have any input or experiences??

all i use is sunoco 94 and i get it at the same gas station every time no ping for me yet it sounds weird but it works so y change it

Originally posted by bigb_9_99
all i use is sunoco 94 and i get it at the same gas station every time no ping for me yet it sounds weird but it works so y change it

Same here,sunoco,It is a new station saw the new tanks go in so I go to same one.I always put 93 in(do not want to spoil it),no
trouble yet.

it is definitely a known fact that different fuel suppliers put various additive packages into their fuel, cleaning agents, anti-det products, etc.. etc...

So, I could see that being possible. I know out of my own experience that one gas stations 92 isn't or doesn't have the same affect on my car as anothers ....

Is it something to really watch out for? Probably not. If you're running high boost, larger turbo, etc.. etc... I'd probably pay closer attention to things like that.

If not, and your the average driver, I wouldn't really worry about it.

Throw some GTA in for piece of mind.

http://www.need4speedpower.com

I've been using Cheveron 94 since i have purchased my car. No problem yet...I also get the most milage from them.

Vishnu told me that 76 has the most consistency in the East Bay. Chevron is way erratic with lower than posted octane...

I've got pinging when I used 1 tank of Chevron, so I'll never go back. 76 has been great...

I change gasolines frequently but always use 3 different types at most and I mainly use 91 octane, and sometimes 93-94

It seems like sticking with one consistent gasoline would help the ECU properly adapt. If you switch around to gasolines with different actual octanes and different oxygenators (ethanol vs. MTBE), the ECU will have to relearn each time you fill up.