MikeWS6

I usually put in 93 but is it needed? stock/bolt on ls1

Finkledbody

I hate Maine. All we have here is 91. If we sold 93, she would be drinking it. My 6 banger gets 91 even though the book says 87. Am I wasting money? Maybe, peace of mind is priceless though.

Exeodus

iTrader: (1)

Octane rating is a gasoline's resistance to detonation (spark knock). Since these engines have relatively high compression for a street engine I would put in no less than 91 (93 even better) for peak performance.

RPM WS6

iTrader: (3)

Actually it's more than just wasting money, by running 91 in a motor that calls for 87 you're also reducing MPG and engine performance. There should be no peace of mind in that.

Best power and MPG will be achieved when the lowest octane that still 100% prevents detonation is used. You want combustion to happen as easily as possibile without detonation; and higher than necessary octane will cause slower/later than optimal combustion. Engines with high compression/aggressive ignition timing, and/or forced induction will want higher octane. A stock, NA 3800 Series II V6 will do better in all categories with 87 octane.

99FormulaM6r

iTrader: (2)

I wouldn't put premium in a 3.8 unless you have a tune or anything like that.

1gt2nv

iTrader: (5)

Or a supercharger! My comp g gtp calls for 91+.

MikeWS6

k cool ill stick to 93 thx

71novaguy

iTrader: (2)

Incorrect, it calls for 91+ for maximum performance, but can run on 87. I actually ran my best 1/4 mile on 89 when I had my 04 GTP.

Back to what RPM WS6 said, yes! You ever get the feeling that people have no sense of direction and follow whatever they hear? Putting 91+ in the 3.8 (n/a) is just about as pointless as the people running sythetic oil and changing it at 3k.

KILLER-LS1

iTrader: (18)

haha i understand your analogy, but there are also MANY MANY more benefits to synthetic than just oil change intervals. i change my synthetic every 3k miles on my turbo car.

so your analogy should be, "Putting 91+ in the 3.8 (n/a) is just about as pointless as the people putting a "tornado" air intake on their car. just wastes money and time....

Finkledbody

Couldn't agree with you more. I've put 60k miles on this car now and for the first 1 or 2 thousand miles I ran 87. For some reason it ran like **** leaving me to believe it was dynotuned by the previous owner. Could never confirm it though. Switched up to 91 and the car ran smoother, ticked less and started getting better mpgs. Just my experience with this car. Dynod the car a few years ago and put the numbers down I'm showing in my sig which was more than I was expecting for a bolt-on 3.8.

Again, Agreed. Will I stop. Nope. Would I recommend this to anyone else. Nope.

SuperSport346

iTrader: (2)

I used to run 87 in my LS1, since premium is only recommended. I never had any problems, and it ran just fine.

More recently, I've been putting in at least 89. I usually put in 93, put sometimes I mix in some 89 to make it closer to 91.

Finkledbody

Read your post a few times. I did and my IQ dropped a few points.

Camaro_94

iTrader: (5)

I only put 93 in my Camaro.

SexyTransAm

iTrader: (6)

93 for my lt1

SuperSport346

iTrader: (2)

I misspelled a word, but there's no other spelling/grammatical errors. The last line is a little messed up though, I must admit.

RPM WS6

iTrader: (3)

LOL, yeah I get that. I shake my head every time I hear about someone putting race gas in their stock LS1 too. I think most people don't do much research on anything before "giving it a try".

Sound like yours is a special case then, possibily due to a mechanical or electronic fault causing less than ideal air/fuel delivery, poor feedback to the PCM, or lazy electronic adjustments/metering (a gumed up MAF due to an over-oiled K&N is a common cause of this). Or, since the car seems to dyno well and make good power, and you bought it used, it's very possibile that you have an aftermarket tune with an aggressive ignition curve and leaner A/F ratio that requires higher octane for proper performance.

I'd probably toss a scanner on it and see where the timing is at compared to a stock L36, just for the hell of it.

02 BLK WS6

iTrader: (11)

93 or higher octane for the jug.

myk

iTrader: (4)

If the book calls for it, then run it. Don't listen to the penny-pinching dick heads that insist on running lower octane "just because they can."

ScreamingEagle

iTrader: (3)

I can't understand why people buy these cars and whine about running 91+. If you drive 10,000 miles a year and average 20mpg, the difference in 87@2.80/gal and 93@3.00/gal is only a savings of $100 a year. If you can't come up with $0.27/day you should've bought a scooter and not an F-body.

justin455

L67-L32's can be all over the place with knock. A bone stock car can show more KR than a car with a dropped pulley and just a D/P. I believe you when you said you ran your best time with 89, but there are some many variables day to day that the octane of gas you used can hardly be pointed to as the reason you were faster.
I always ran 91+ in my L67 and would never think to run anything lower without a scantool.
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