Gasoline question

[Sleighboy]

You people are way over myhead mostly, but I wonder about using various grades and manufacturers of gasoline.

First, I have the '03 GT and mostly use mid-range (89) octane gas. the dealer said to use high (92) octane if I was going over the mountains or wanted to get the most performance out of my GT . . . this was in response to a question I had regarding an article I read that said that the PT GT model is one of the few vehicles that actually improves it's performance when using high octane gas . . . it's a chip thing I think? Anyone have some thoughts on the subject? What about using regular gas in the GT? I don't, but . . .

Secondly, what's the deal on gasoline in general? I was told not to use Costco or the cheaper companies gasoline due to long term engine sludge problems. Isn't all the gas the same now-a-days? What's the real story here? [:0]

[Gary04GT]

Since you purchased a GT Turbo I assume you want to get [u]optimum performance</u> from your car--use premium gas (91 octane or more). While you can use regular gas in the High Output Turbo premium fuel is recommended and should be used to obtain maximum performance from the engine.

I have been using Chevron gasoline for over 30 years and have been totally satisfied with it. Chevron has an additive--TECHRON--which works to keep the inside of your engine clean. In my GT Turbo I use Chevron Supreme gasoline (92 octane) all the time whether or not I'm driving in the mountains or not. Chevron gas has worked for me! [^]

[Jeff V]

I think there's a sticker inside the fuel refill door that says "High Octane Recommended" or "Premium Fuel Recommended".

I have 9,500 miles on my 03 GT and have used nothing but Exxon 93 Octane. I have been happy with the way the car performs - I have an automatic (ugh, I know, first time ever) and I can chirp wheels any time.

I can't compare to "lesser octanes" since I have only used 93, but as long as I get that feeling of being pushed back into the seat when I wot, and crushing rice jalopys with the 3" pipes out of the street tree, I'm happy. And I do.

[RD CHILI]

Costco gas is just fine. Gas is just as good, as it all comes from the same refineries. Some just have / add additives, including Costco.

[redrum]

sleighboy--i have used the gas @ the same costco you use. i used it in a modified s10. the mods recommended that i use premium gas. i had been using the gas @ the edmonds quick & clean with no problem. when i filled the truck with the premium unleaded costco gas, it would ping somewhat. no ping while using the union 76 down the hill into edmonds. the gas @ the union 76 is usually cheaper than anywhere else ('cept Costco). tuesdays they cut 6 cents off the price of a gallon of gas. i know costco is quite a bit cheaper, but for the difference in cost, i recommend the gas just down the hill into edmonds. we are talking about a couple of bucks a tank.
r u coming with the rest of the puget sound cruisers this weekend to the lemay museum? if so, see you then.

redrum
03 GT

[Sleighboy]

Thanks to everyone for their two cents worth. I've never actually used regular in my car, I was more curious than anything. Yes, I'll be there at the Poodle Dog Restaurant for the cruise . . . guess I'd better go fill up at the 76 station or a Chevron station tomorrow . Still open to more input on this whole topic.

While we're on the subject of gasoline . . . what's the deal on these @$&%*#! price increases! I thought our oilman Pres. was supposed to be watching out for us? [:I]

[THier]

Sleighboy,
If you are a jolly fellow with a big white beard, and bought a red cruiser I have a list for you, its a big one but you still have allmost 10 months.
Just kidding, on the question of octane, high octane gas does not give you any more hp, in fact octane is kind of like a burn retarder, BUT because of the higher cylinder pressure, caused by the turbo forceing air into the combustion chamber, the fuel wants to light before the sparkplug fires, fuel fires as piston is still moving up, and you get knock, this is where the higher octane comes in, it hopefully won't light untill the right time, untill you raise boost ect and build even higher cyl pressure, hense the race gas switch on S2. Some people used to inject water into intake to do the same thing, basically. With todays computers you shouldn't here knock, it senses it and retards timing and does other thing to try to prevent knock. When i picked up my GT anTWERPen motors put reg gas in it and it was a slug, the first tank of 93 made a huge difference[8)].
Tom

[MichaelDay]

Sleighboy, lets think for a minute about the difference between the High Output Turbo and the 180 HP Turbo. The High Output Turbo is setup for Premium fuel to produce its rated HP. With a lower octane rating, the PCM will make adjustments to avoid engine damage and thus reduce horsepower. The 180 HP Turbo-lite is the same engine with a different PCM calibrated to run on regular.

So, it would seem that if the PCM in the HO Turbo modifies its settings to accommodate regular that you have now turned your HO Turbo into a Turbo-lite. However, the PCM in the Turbo-lite does not take advantage of premium fuel to increase its power above the 180 HP level.

So in short, the PCM in the HO needs premium fuel to develop its rated HP and the PCM in the Turbo-lite needs regular fuel to develop its rated HP.

[mcruz]

Jeff V, nice ride, looks familiar.

[THier]

Sleighboy,
Now I feel stupid, I just clicked on your link[)]
Tom