Regular vs. Premium

Ok, first off im sorry for starting another thread about gas but i felt it would interfere with other peoples questions which seem to be more important than mine..

After reading this

Never put anything lower than 91 octane in your car!!! That would also explain the gas milage... And in fact your gas milage really isnt that bad. For town driving thats probably the most you will see. Always put 91+ octane in, if you cant afford it, you cant afford a turbo car so dont drive it unless you feel like replacing the motor when you melt your pistons

I became somewhat worried.Is that really true? Ive heared alot of different things from different people, like its ok to use regular gas when you you are using the stock turbo, or you can use regular if you dont push your car hard. What should I do? Premium is expensive ass hell and eventhough gas is going down slowly. What are your opinions/ experiences? Thanx for the input

If you have a logger just watch for knock. IF it doesnt knock with regular you can get away with it. Another reason everyone should own a logger... But I still would risk it. I run 93 exclusively. At least mid range gas. Its usually only about 10 cents difference between grades (20 from 89-93, thats a bit more noticeable).

the way i figure is that eclipses (1g's anyway) have about 13 gallon tanks around here premium(94) is about 15-20 cents more then regular thats only about 2 bucks extra per tank so why risk it?

I would run premium no matter what, expecially if you dont have a logger. Better to be safe than sorry.

yeah, PREMIUM!! and more than just the "safety", you can just notice that ANY car, n/a or turbo will run a lot more healthier and just perform better. right now i am driving a cavalier cuz my car is gettin an engine swap. i have tried regular and premium and WOW!! the difference is crazy.

I can even notice when people are running premium or reg in their cars, I ask them and I am 90% of the time right and if I am not, it is cuz they suck at regular maintainace and care.

my two bits...

this gets me,everyone that says this place is cheaper and so on.i look for the cheapest place but think about it.say that the citco is cheaper but its 5 more miles than the sunoco thats six more cents per gallon.you waste that extra six cents cheaper driving to the citco.


does anyone see it the way i do?

^ Yea but it does not take a gallon to drive 5 miles so that is less than 6 cents. Also you are filling up ~10 gallons so thats 60 cents in savngs.

my friend has driven his 96 GS-T for years on 87 octane. His car is f*cked up, but still gets you from A to B.

He does pizzza delivery using this car....he filled up with 91 octane a few days ago, and was astounded to see that his gas mileage had improved drastically, and this tank of permium gas was taking him much farther than 87 did.

If you're lucky enough to live in a city that has QuikTrip, you should buy your gas there. I may be biased because I work for QT, but our gas is Top Tier rated and in some cities, you can get it in 93 octane.

In my city, kwik-trip has the worst gas, other than the shell station. Sure they have 93octane, but the Mobil and BP stations here have much better gas. The BP has 93 too, so i always go there. I usually put 87 in my car, just because i have no money, that 2 dollars is big for me(high school), every now and then though, i get premium, just because i found some money, then i buy the expensive stuff.

I never saw a mileage or knock difference between stations. But with the truck Mobile diesel, while significantly more money than the shell I tend to use, gives much better mileage. About 75 miles per tank. But figure that I have a 35 gallon tank, and factor in the price difference, its still cheaper to run the shell diesel. For the car, it all worked out the same in my case...

93 all the way!!!! I have filled up on 91 before. I got 260 miles to the tank of gas. On average fill up of 93 I get a little over 310 miles to a tank of gas. I don't floor my car when I drive it. I "pansy" drive it. On a interstate trip I get 32mpg out on the highway and about 17 in town. All on 93 octane.

Cheers,
Ben

P.S and off topic but....I changed my plugs to the NGK BRP7ES or something like that. Did any of you guys who have changed your plugs notice a decrease in gas milage? with this change in plugs?

bastards with over 91... come to cali and we'll see who has the crappiest gas!!!

the only things that the octane of gas is going to effect is performance and gas milage in high performance applications you couild run in to detonation but for your every day driver you can run pretty much any octane with out a problem
the higher the octane the slower and hotter the gas is going to burn

I have always put 93-92 oct in and my wife used 89 once without knowing and there was a noticeable difference in power and how smooth it ran... wanna try a 93-110 mix someday......tee hee

I might be wrong but isn't it the higher the octane the faster and hotter it burns?--(96probegt-log)

Higher octane tends to burn slower. But the burnrates are actually very close. It is more accurate to say it doesnt ignite as easily. :) BUt this is a very complicated subject, and I could go on for another novel here...

Changing plugs shouldnt affect mileage unless you didnt gap them properly. Gap can affect economy for sure.

Edit> Its also worth noting that how the car runs on 87 depends on the car. In my case, if someone acccidently put 87 in my tank I would lose the motor, no question in my mind. And it has happened to other people with well modded cars. One guy lost his motor when his GF tried to be nice and fill his tank for him after borrowing the car. I feel bad for both of them. Thats one reason I only run premium and I make a big deal about it so anyone that could potentially use my car doesnt make the same mistake. Its also nice to have things like DSMlink that warn you when you are kncking, even when you are not datalogging (CEL comes on at over 3 degrees of knock retard).

Thanks guys great info you've convinced me to use premium, after i thought about it 2-3 dollars a tank is nuthin to worry about haha thank god for AF.com