premium gas needed?

[DirtBike1128]

im hopefully about to get either a GSX ( hope hope hope) or a GST. i realize that with most engines, the higher octaine you put in, the better the car runs, but i was just wondering if the turbo DSMs really need premium. im just thinking that they do because of the turbo, but i hope not.

[spyderturbo007]

Here we go....I hope I get this right. TECHNICALLY speaking you do not have to use premium fuel. The reason you are supposed to is because the higher the octane the more resistant to knock, or pre-ignition the fuel is. The eclipse ECU naturally advances the timing as far as possible during normal engine operation to provide you with the maximum amount of power. But this increases the possibility of knock. If the ECU "hears" knock it will retard the timing until the knock stops. This results in lower performance and less power but is nice because you won't blow up your engine. With 87 gas the ECU has to retard the timing a good bit and MAY also have to limit boost levels....which really sucks! So my opinion is USE PREMIUM FUEL all of the time. There is no reason to put your engine in harms way to save $0.20/gallon which is about $2.40/fill based on a 14 gallon tank. Also if you are concerned about the $2.40 per fill I am guessing you aren't going to use the $5.00/qt full synthetic oil at every oil change. May want to look into something else if money is tight. Eclipses are GREAT cars and I wouldn't trade mine for anything in the world...but they do require constant maintenance. But where else can you push the stock internals in a motor to run a 10s ¼ with nothing but bolt on mods. Sorry to ramble but I hope this helps. Good luck!

[ashah000]

In one word... YES

[FourG63 97GST]

I've never tried runnin lower octane.

but i'm surely loving this $1.97/gallon right now

[my97blackgst]

I always run 93 octane. Once I had to run 91 and I could tell a difference. Thankfully 93 is only 1.70 around here.

Cheers
Ben

P.S Spyderturbo007 nailed on the head.

[DirtBike1128]

man, a few years ago here in NJ, i remember looking at gas station boards and seeing $.83 for regular. those were the days!