5.7ltr SS - premium unleaded v unleaded???

[SimoVXSS]

98 is all i use, didnt matter what the car was.

Its a cleaner fuel, burns more effeciently and better for your engine. Worth the extra $3-$5 IMO

 

[VZ SS :D]

Well gone through a few tanks of both 98 and 91 fuel and to be honest i cant tell any difference, maybe a little in kms/tank but might just be from different driving.

 

[CANYONERO]

i only run mobil 8000 or BP ultimate in the Vy, there the only fuels i use in it unless i go back home ( small country town) with a liberty or shell. so i only put in enough to get me to the nearest BP and fill up. i think its worth the bit more but usually my car sits in the shed most of the week and only used on weekends, i got gas in my daily for the grind to work an i put in whats easiet to get.

 

[Lumps of cheese]

Well gone through a few tanks of both 98 and 91 fuel and to be honest i cant tell any difference, maybe a little in kms/tank but might just be from different driving.

Has it been tuned?
You won't really notice the difference until your car has been tuned. Most tunes are set up to run specifically on 98 or in some case 95. Since my tune i've ran 98 all the time and the difference in economy and proformance is quite noticable.

 

[VZ SS :D]

Na not yet, I plan to get one though

 

[cpbait]

the difference between 91 and 98 is about 3% in power difference and economy, they are set up to run both from factory, obviously 98 will be a bit better, this is what i was told and shown on a efi performance course i did, i personally use 98 about 99% of the time, have put 91 in to see the difference and for the extra couple of dollars the 98 is worth it, i got better economy and felt better out of it, have used 95 before and didn't notice a real difference between 95 and 98.

i use shell 98 and if just a little top up will put 91 in, have just put carltex 98 in this week.

my trade school teacher said you can use 91 during the week and will be fine and put 98 in on the weekend for a bit of fun

 

[Brail]

I have run a two month test on this very topic using 95 for a month and then using 98 for the following month. My car hasn't been tuned specifically for either fuel and what i found was that for the price difference in the fuel compared to the difference in mileage gained from the higher octane fuel the difference is very very small. 98 won the battle but you could really call it a tie. I quess it comes down to having the benefits of cleaner burning fuel and less engine wear from the 98.

 

[rb26dett]

Just use regular unleaded until you get the tune.

 

[coolvxss]

My car is stock, and have tried both fuels and cant notice a difference

 

[DevilDRake]

My shitty 1997 Hyundai excel sprint, after going from 91 to 95, it makes a pretty noticeable difference.