ok i dont feel like searching its late i gota work tmrw. i have a se. would it hurt it to run premium? or should i keep it unleaded.
its not fixed up or anything just stock. but im thinking i might get better mpg. and it might be better in the long run for the motor.
but is it true if you start running higher octane u should keep doing it as its bad to go from high to low. but not bad to go from low to high octane? make sence?

thanks

There is high and low octane tables in your pcm'* programming. Depending on the grade of fuel you use and how well your car is running, it is very possible you could find increases although they might be small.

We have members in both categories..some run premium and find a noticable difference and others have run it to find no change.

Give it a try and check your mileage etc.

There is no extra POWER in higher octane fuel. Higher octane is simply harder to ignite. Cars with knock problems or Forced Induction use it to keep the A/F mixture in the cylinder from igniting from heat and compression before the spark.

Your car may benefit slightly from it IF you have KR with your OEM setup. Some see small gains with mid-grade, which is probably the most I'd spend on fuel IF I owned a scantool and proved to myself that it gave me more timing.

I'll repeat:

Premium fuel has no ability to increase horsepower or fuel efficiency by it'* formula. It'* simply harder to ignite.

Personally,
I'll take high test everytime,
I don't know all the technical jargon all I know is from experience when I step on the gas pedal premium has always gone faster.

I have no charts just know what I have seen. dragster'* should just run low test and save all that money they spend on nitrous and stuff.

Give me Sunoco Ultra, others keep using 87 whatever.
Wish we still had Blue Sunoco, back in the days of 140 octane, now that was gas. Today what we have is just corn likker.

Peace, you're misunderstanding.

You are Supercharged. YOU need to run 91 octane MINIMUM.

HE doesn't. His car isn't supercharged.

True statement. Higher octane ratings do not mean the fuel is more potent. One would probably be better off spending a few extra pennies on a quality regular gasoline that has better additives than QuickieMart premium, provided your car is designed to run on regular.

Having said that, I used to run mid-grade in my 93 SSE (NA) and got better mileage out of it.

from my experience with running premium in my cars, i have always gotten worse mileage with no performance gains. granted all of my cars have been 8+ years older than yours so the technology my be way different.

i am currently running mid grade in my blazer for the sole fact the i have some pre detonation that i am unsure of the cause yet. other wise it would be 87.

ok so it wont hurt to try it? and then go back to unleaded if i dont see a diffrence? im not looking for more hp or anything. i just dont wnat my car to tweak out on me if it takes it the wrong way :(

and is it ok to mix? i always keep my car full. if i run it as dry as i can and fill it with premium would it hurt it?

It will not cause any damage to try higher octane. Figure your typical MPGs on regualr first, then compare to premium after a few tanks. Figure in the cost difference... It may be hard to feel any performance benefit or deficit, so a scan tool can tell you for certain about advanced timing. But again, make sure to scan on regualr first so you have something to compare to.

Put it in at any fuel level. It won't hurt anythng.

Believe it or not, LOWER octane actually makes fractionally MORE power than high grade. It ignites faster, produces a more powerful explosion in the cylinder. But it really is fractional, completely unnoticeable...