I have a 95 z28 which I only run premium gas in because i was told that with the high compression in the LT1 you have to run. But i was wondering if this was true because im kinda sick of paying 3.60 a gallon.

 

Check your owner's manual and it will tell you what is recommended. I have a 98 LS1 and it recommends to run premium for optimum performance but will run on 87 with no ill effects except a possible drop performance.

 

3.60 a gallon... i pay 3.81 a gallon for premium.. Premium fuel burns slower thus your engine adjusts to that slow burning fuel when you use regular it burns faster and even tho your engine is wanting to burn it slower its not causing a bad air/fuel ratio. If you cant foot the bill to run your camaro right, what i do is fill it up with premium when i can and wheni get to 1/2 or quarter tank i fill it up with plus. Mixing the octanes will result in a higher octane gas.

 

You can run your car on 87 octane, the computer will automatically retard the timing so you don't have engine knock. In retarding the timing you are going to experience a loss in power, and it's going to be noticeable.

 

you mean mixed octanes right? half and half 91 and 93 will average out to 92, its not an additive effect. Im sure this is what u meant, it was just a little unclear.

i disagree with the first part though.... kinda. yes, higher octane burns slower, but its not about how fast ur engine "wants" to burn it, and it doesnt affect AF. the slow burn means its more resistant to knock, the only issue you run into with gasoline is that knock causes the computer to retard timing. if its doing it alot you will be running on perpetually retarded timing andtherefore making less power (the computer usually overkills the amount needed as well). in a high compression motor like the LT1 and LS1 I would always run premium.


and slvr, the computer doesnt do it in response to the gas, it retards timing in response to "percieved knock" which means if its happening, you are still getting knock, just sporadically. ur engine can tolerate this for awhile, but its still bad. even burst knock shortens engine life, its something we all live with, especially if you have a manual and have a tendancy to let ur RPMs be pulled too low while driving. just because its a fact of life doesnt make it any less harmful so minimizing it is always a good thing

 

Yeah, it makes it even out thats what i ment. Like you said if u fill up with premium then add plus later it will be higher than plus. However by burning slower its able to burn more effectivly and like you said about the timing it makes more effecient power off the fuel over regular as it retards the timing.

 

I would have to say that I agree with Specter, because if I don't run premium I get a horrible knock and when I do run premium it goes away. The extra 20 cents you pay for premuim compared to 87 octane is worth saving your engine, what is 3 more bucks every time you fill up compared to buying a new engine

 

Spec, I didn't mean that the computer realizes that it has a different octane in it, I suppose I was a bit unclear about that. I meant it to mean that with a lower octane the computer is going to try and advance the timing as much as possible, but it's not going to be able to advance the timing as much with a lower octane fuel.

 

i figured u knew what u were talking about. its just such a hairy subject its best to be as clear as possible

 

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