5.7ltr SS - premium unleaded v unleaded???

[Dr.304]

I will not be using anything more then 95 octane when i feel like it.
Other than that 91 octane here i come!!

Ive owned too many cars where 98 octane is a must!

 

[CommVTS]

The bloke that's dyno tuning my car says to always run 98.

 

[wrx884]

i Run 98 75% of the time, usually switch it up every 3rd time and use normal unleaded.. seems to get more mileage out of the normal and premium tanks when i do it.

ive been doin exactly this and 2 my supprise ive been gettin more mileage out of normal unleaded aswell. only noticed this over the last few months tho wen i decided 2 try 91 4 a change.

 

[blow thru]

You want to run through a couple of tanks of 98 to benifit from the higher octane as the pcm will relearn itself to adjust.As for goin from 91-98 in price difference just forget the bottle of coke an mars bar an then its the same price. win win situation

 

[JD]

Really depends on the car, for all the V8's i've owned, i've always ran 98 ( or 95 in extreme cases when 98 was not available ) but with all my 4 or 6's never bothered with it because they were runabouts anyway.

 

[QWKLS1]

you wont notice the difference. i never did b4 and after tune in my old rig haha.
but when u get ur car tuned stick to the same fuel they used at the time

 

[kieran.87]

i run 98ron and every second tank or every tank if i can afford it i put in a octane booster.

 

[Bravotwozero]

Burning anything higher than 91RON in a standard LS1 is simply a waste of money. Unless you're tuning to run the higher RON then you won't see any performance benefits whatsoever.

Remember, octane rating does not relate to the energy content of the fuel. It is only a measure of the fuel's burn characteristics. I higher octane fuel will have a more controlled burn allowing more agressive tuning and higher rcompression. Hence more power.

Octane boost will do nothing but empty your wallet.

 

[wikky]

Remember, octane rating does not relate to the energy content of the fuel. It is only a measure of the fuel's burn characteristics. I higher octane fuel will have a more controlled burn allowing more agressive tuning and higher rcompression. Hence more power.

Octane boost will do nothing but empty your wallet.

Correct. Octane booster requires a tune adjustment (timing) to be of any benefit, but you wouldn't run your car on booster so it's pointless.

 

[boneart]

95 vs 98

I hadn't thought of using 98 at all as I have an account with Shell who in my area only do 91 & 95. I have been running my VE SSV on 95 for 6 months.
Did a trip down country and no Shell stations around so filled up at BP on 98 not expecting anything different.
I was very surprised when after a few ks the car seemed to me to have a bit more pep with cleaner throttle responses and smoother running, particularly when doing some "spirited" driving.
I don't know that it was any more powerful, it just seemed smother and a bit more agile.
Perhaps the previous owner had run it on and had it tuned for 98 or perhaps the 6ltr V8 just likes a slightly higher octane, I don't know.
Its all gut feeling with no figures at all to back it up but what made it interesting was that I was not expecting any change so had no preconceived ideas of what it would do.
I enjoyed the smoother performance so will be changing over to 98 (whenever I can get it) for a few months to see what its like.
From reading the forums and doing a bit of other study etc recently it looks like there might be a small economy improvement which should cover the small cost increase so I can't yet see any downsides.