Endersshadow

iTrader: (1)

Octane boost is useless. Raises the octane like .4. Waste of money.

TAtoad

iTrader: (22)

I always run 93. every now and then when i'm only putting 5-6 gallons in i'll get 89. runs fine. never used Regular tho

zacht

iTrader: (18)

nice...good to know the ase certified mechanics refuse to follow such simple recommendations...

guess the "low octane" timing tables in the computer were just bs....

i agree with most all the people in here..run the right fuel as suggested from the manufacturer..

DWake

iTrader: (1)

It makes sense they do it to save money where they can because the car can run on 87. But I do have to pitch in that I ran 89 for 2-3 tanks when I first got my car, then I ran 93 and it was a noticeable difference in power and I got a little better MPG. When 93 is 20-30 cents higher than 87 you are only spending 3-4 bucks more for your car to perform its best.

thunderstruck507

iTrader: (18)

My basically stock 5.3 Silverado pulled timing on the stock tune with 87 octane...if you run that crap in a higher compression LS1 you probably just need to get a different car.

To the OP: be easy with it, avoid any high load situations that lug the engine and no WOT pulls. If you can, siphon the crap out and use it in your lawn mower or another vehicle. If you can't try to cruise out of overdrive and upshift less to help burn through the crap quicker. Try to get below half a tank then fill up with the best premium you can get.

brendo389

I've only ever run 87 in my TA, twice. Both times were when I was down to empty and didn't want to risk running out the rest of the tank on the way to the gas station, so I used very little of the 87, and wouldn't get anywhere near WOT under fear that something would break. Don't beat on it until you're sure at least the majority of the 87 is out of the tank, then you should be fine.

Drew WS6

My T/A has never had anything less than 93.

NC01TA

Same here. I just follow the recommendation of GM.
Click on the photo to read it. This label is on my '01 T/A gas lid.
Attachment 377912

z-maro

iTrader: (18)

shyboutin

Holy **** guys. .. I wish I would have known this. I have ran my cat hard and all I put in mine is 87 or 89... that's all that's in my town... I'll be filing it with 91 or 93 here soon to see if I can feel a difference.... I have exhaust, long tubes, cold air, intake manifold, 3.73 s etc.... not sure if I have a stock tune. Could I have been hurting my car?.... I am throwing codes for heater o2s and system lean banks.... but I averaged 24 mpg last time I filled up but I didn't get on it much. Btw I'm in a auto 2000 trans am

Fry_

Yes always fill you car with Top Tier rated 91-93 octane fuel and if you can get it with no ethanol thats even better and your car will likely get better fuel mileage. O2 heater and lean codes are common problems with car that have headers and need a tune.

RPM WS6

iTrader: (3)

It's interesting that you can only get 87 or 89, I didn't know that they shipped specific "89" octane fuel. I thought all stations just had low grade (87) and high grade (91 or 93) octane tanks and then the pump would mix them to achieve mid-grade (89) when selected.

Seems like a waste to store specific 89 octane fuel since so few applications call for it. In fact, I've only ever used it in my lawn equipment as it seems to make those engines run a bit better. I've never owned a car that needed anything but regular 87 or 91+ premium.

Fry_

It was very common here in small Iowa towns until they stopped refining gas to 87 octane. It was always 87 octane was ethanol free and 89 was E10. But some time it the last year or 2 all refineries stopped making 87 octane, and instead produce 84 octane and add either 10% ethanol or 93 octane to get it to the required 87 octane minimum. Now most stations sell E10 87 and ethanol free 87 that cost $0.30 more, and if you want 91 you have to go to either a bigger town or the interstate and pay $0.45-50 more. But at least every BP and Phillips 66 Station that I've seen still sells ethanol free 91, just steer clear of all Casey's gas it's low quality crap. It's strange how different things are even though your only 1 state away from me.

jimmyblue

iTrader: (11)

The 87 octane will ping and drive knock-learning spark
advance toward the low octane table. It will take some
time to crawl back out of that hole. Even Shell V-power
93 made my car ping once I had it tuned up tight to a
decent (BP, Chevron, Sunoco) 93.

I'm not convinced that you couldn't get the LS1 to run
OK on 87. In fact I wonder if it might run better at high
RPM with less octane (when suitably tuned) because
you need the fat slow burn for torque and anti-ping
but slow burn isn't so great for high RPM. You see
people leaning out the top end fueling for this, so....

But I've never seen anyone take the time to try and
do it right. Maybe because the consequences of
failure can be severe.

Orange Juice

iTrader: (3)

Most octane boost additives are crap, I carry a can of this with me if I'm travelling somewhere that may not have stations carrying 93 octane.
http://torcoracefuel.net/pro-accelerator.html

FirstYrLS1Z

iTrader: (4)

in response to post #34 by 'jimmyblue' of his 2nd & 3rd paragraphs.
My engine is stock except for SLP CAI and StainlessWorks catback system(they used my car for prototyping so I got the system and installation very inexpensively).The Stainless system did nothing for the 1/4(same times before and after). But to the point. I'm approaching 190,000 miles and use 87 octane since I got it at 30,000 miles. The 1st Sunday in august over the years,Thompson Drag Raceway would have GM vs Ford day. I always participated with the local group but only do the test and tune session runs. I would always start using 93 for about a week before the event. One time I didn't change over to 93 and ran with 87. Best times ever ! Looking back that day,the only change was not using 93. So for the following 5 years I tested. 93,87,93,87,93. Always turned better times and felt stronger with 87. As far as using 93 for about a week previous to racing,Scott Settlemire,F-bod godfather,said it wasn't necessary as the computer makes immediate changes as required,that's what the computer's for. I've come to the conclusion that a gallon of 87 contains more combustible fuel compared to a gallon of 93 where some of that combustible fuel is replaced the flame retardant additives. Let the 'flaming' start,I don't care as I know what my Z runs best with and with 190,000 miles 87 hasn't 'hurt' it.

RPM WS6

iTrader: (3)

Specific octane requirements will be affected by timing and A/F ratio, among other things, so if your tune isn't on the ragged edge for street fuel or is overly rich, or you are on a stock tune that is running overly rich for some reason (deteriorated O2 sensors, dirty MAF, un-tuned bolt-ons, etc.), then the extra octane may not be needed for best performance.

I've said it before and I'll say it again, you'll always be fastest when using the lowest octane possible that still 100% resists detonation. If your setup is such (A/F, timing, compression, intake temp) that you get no detonation on 87, then there is not going be anything to gain with a switch to 93 (if fact you will lose performance, as you've seen) with all else being equal. Having said that, if you are getting no detonation at all on 87 octane with a stock compression LS1, then you could likely lean your mixture and/or bump timing a bit for a noticeable increase in performance while using 91+ octane.

RevGTO

iTrader: (12)

All we can get in KS is 91 octane and my car consistently gets some knock retard with it in the peak of the torque band. I've even pulled timing in that range and I still get it. There was an octane booster called "Octanium" available for a while that actually worked, and I saw some of my best times using it, with the logs showing no KR. On the other hand, I tried mixing some Toluene with my gas and that boosted octane too much, and it really slowed me down. The point is, as RPM says, you want to find that sweet spot where you can run maximum timing for the lowest octane at the highest VE that will keep you detonation-free.