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LT-1 gas info



After reading the comparo between the LT-1 qnd the LT-4 (besides wishing mine were a LT-4) the next item that popped out at me was the gasoline octane requirement - Regular versus Premium. I have ran High test in mine as I think that is what is recommended in the manual. On the other hand I have not systematically lowered the octane to find where it knocks or detonates - which is what octane seems to be all about. Has anyone used regular gas without any detremental results? ............ when building motorcycle engines (both rebuild and racing) I would use the compression ratio as a guide to determine which octane to use and lower or raise the octane systematically from there - as we could use anything from 87 to 105. Am I reading this comparo correct? or is that a typo of sorts? ........ thanks.
Premium fuel has no more power than regular fuel (the molecules are identical). What makes a high performance engine run better on premium on is that it has impurities in it that make it burn slower. This allows more timing advance which can improve power. The newer corvettes have an anti-knock sensor that will automatically retard the timing. So what this means is you will never here the engine knock or detonates.

The consequences of running regular fuel is less performance not injury to the engine (my 2001 Silverado can actually identify octane ratings). I use 92 octane on my LT-4 and it appears to function fine (ran 168 MPH with it). I have used the 105 octane and have not been able to observe any performance enhancements. Also altitude can lessen the need for high octane.
Only Premium....

I have a '94 6 speed LT1 and have only used premium -93 octane - as that is what is marked by a sticker right at the fuel tank filler. My understanding of premium is that is burns hotter and more complete than regular. I wouldn't take a chance and burn regular in a performance engine. Once you start playing around with pinging, it's hard to clear it out. Besides, if you own a Corvette, why would you try to save pennies on gas in the first place? Anything that would maximize not comprimise performance would be the choice!
warsawwizard... you can run any octane from 87 to 105 in your corvette without hurting anything. The microprocessor will not allow pre-ignition or donation to exist more than milliseconds. What suffers is performance. The microprocessor retards the timing to prevent it.

POWR TRP your right about the choice for premium with a corvette…the engine runs better on premium fuel and the costs is minimal, however, premium fuel does not burn hotter or more complete than regular…look at the chemical equation….oxygen+carbon+hydrogen…that's it folks…complete combustion gives you H2O and CO2. Tetra ethyl lead does not make anything hotter; it makes the oxidation of the hydrogen and carbon slower. 87 octane will not hurt the engine…just makes not perform as well because the microprocessor retards the timing.
I have run regular gas in my 94 without a problem for the last year. My 86 pings slightly at WOT, just enough to notice before the timing control retards.
I've been running 89 octane and it's just fine. I drive my car a lot and with gas prices continuing to rise here in Chicago, I'll be staying with 89 unless a trip to the track is planned.

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