Fuel octane 94 lt1 engine
03-22-2012, 08:45 PM
#1
Pro
Thread Starter
Fuel octane 94 lt1 engine
Ok, does anyone run mid grade or 87 octane in your Corvette. My owners manual says --------Use premium unleaded gasoline rated at
91 octane or higher. You may use middle
grade or regular unleaded gasolines, but
your vehicle may not accelerate as well. ---------I am not pushing the car, just cruising. I don't want opinions. I want people who have used lower octane fuels and whether or not the engine did or did not knock and that it was ok or not. Thanks
91 octane or higher. You may use middle
grade or regular unleaded gasolines, but
your vehicle may not accelerate as well. ---------I am not pushing the car, just cruising. I don't want opinions. I want people who have used lower octane fuels and whether or not the engine did or did not knock and that it was ok or not. Thanks
03-22-2012, 09:25 PM
#2
Race Director
It shouldn't knock. The knock sensors should "detect" any knock before you can hear it, and retard the timing.
That is the reason for the statement in your owners manual about lower performance.
I wouldn't be doing any spirited or performance driving using regular grade though.
In a pinch (since that was all they had), I have used regular in my LT4. I didn't do any hard driving, and filled with premium on the next tank.
Didn't have any knocking issues, and since I was doing all interstate driving at the time my next fill up was the same day.
Bottom line though, it only costs a few dollars more per tank to use premium.
So, it's not like your going to save a fortune.
That is the reason for the statement in your owners manual about lower performance.
I wouldn't be doing any spirited or performance driving using regular grade though.
In a pinch (since that was all they had), I have used regular in my LT4. I didn't do any hard driving, and filled with premium on the next tank.
Didn't have any knocking issues, and since I was doing all interstate driving at the time my next fill up was the same day.
Bottom line though, it only costs a few dollars more per tank to use premium.
So, it's not like your going to save a fortune.
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Brian1456 (02-03-2019)
03-22-2012, 10:22 PM
#5
Le Mans Master
I drove a 100 mile per day commute that was nearly all highway & interstate. I used 87 most of the time for a couple of years. No problems. I suspect because most of mine was low throttle cruise.
I suspect that if you load it up you may notice more. When I did, I didn't hear any ping (it was a pretty loud exhaust), but it did not perform as well as 93.
If you are using it with more frequent high throttle, I would recommend the 93 for both performance and to prevent engine damage.
I suspect that if you load it up you may notice more. When I did, I didn't hear any ping (it was a pretty loud exhaust), but it did not perform as well as 93.
If you are using it with more frequent high throttle, I would recommend the 93 for both performance and to prevent engine damage.
03-23-2012, 07:36 AM
#8
Le Mans Master
Member Since: Oct 2004
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Note: I fooled around with various "octane boosters" while trying to run an L88 on 91 octane. I suppose 12:1 compression was a bit extreme, but in any case none of it really was worth a damn (and those with magnesium leave rust-colored deposits that will choke the O2s(!), not to mention it is very $$$ and a PIA to keep up with - especially at 8 mpg
). I know that race gas has additives in it to raise octane, but apparently that "witches' brew" they use is not something you can buy at WallyWorld (or the like.)
). I know that race gas has additives in it to raise octane, but apparently that "witches' brew" they use is not something you can buy at WallyWorld (or the like.)...Just sayin!
P.
03-23-2012, 08:39 AM
#9
Safety Car
As Ive said before Natty Light will give you a buzz but Michelob just tastes better.
The Vette gas tank is what, 18 gallons? Go ahead and run 87 and save that $3, you can get another sixer of Natty.
The Vette gas tank is what, 18 gallons? Go ahead and run 87 and save that $3, you can get another sixer of Natty.
03-23-2012, 09:33 AM
#10
When I tried mine on 89 I was of the mindset that if I saw ANY timing retard at all, that I would stick with 93. Now could I run 89 or even 87? Sure I could but for me the cost difference really doesn't justify it. I've modified my car because I want horsepower, and I want that horsepower to be there and available all the time, not just when I happened to choose the right gas. Personally I can't see building a high performance car and then crippling it because of the fuel.
If the Vette is your only vehicle and you only ever drive Miss Daisy and you never press the go pedal for a little fun then sure, run the cheaper stuff and save a few (very few) $$. On the other hand if your Vette is more or less just a toy, and you know that every time you get in it there is at least the potential that you might want all the power it brings to the table, then go with the good stuff.
You can also look at fuel economy, what is your other option? In my case if I opted to take a road trip I could take a road trip in my F-150 or the Vette, F-150 gets about 18 best case on the highway, the Vette easily gets 25. Do the math, 600 mile road trip = 33 gallons in the F-150 vs 24 in the Vette. Say regular costs $4 a gallon and premium is $4.30. That = $132 to drive the F-150 and only $107.5 in the Vette. Personally I'd opt to take the fast one and use the more expensive fuel. Yeah it costs more but if I use less of it I'm still money ahead.
Maybe I'm just the odd one but I think I would rather find somewhere else to save the money. I mean think of it this way. Sure I could put regular gas in it, but then why do I bother with synthetic oil? Afterall if I'm not going to ever beat on it and get the oil hot, I might as well run regular right? But then if I'm never going to beat on it, why am I driving a Vette at all when I could just drive a Camry? I've just cheapskated myself out of a Corvette.
03-23-2012, 10:26 PM
#11
Safety Car
Its a performance car with the programming to take use of that 91 or greater octane. I use my GO pedal a LOT, I get ZERO spark retard at WOT all the time regardless of outside temps/engine temps,etc...why? I run 93 Sunoco.
Run 87 in your Camry this is a Corvette for crying out loud.
03-24-2012, 01:09 AM
#12
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When I fill the 40 gallon tank in my Suburban, it makes me feel good about filling the Vette. The Vette got almost 29 MPG on a trip to the 24 Hours at Daytona back in '01. Haven't paid much attention to the mileage lately, but the best I get in the Burban is 15.
03-24-2012, 01:26 AM
#13
Team Owner
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St. Jude Donor '05
nathan is right on the octane boost scam.
Good stuff right here
http://www.chevelles.com/forums/show...ighlight=kemco
Thing is I think it has lead in it so may affect cats if you have any.
Dont know if they have unleaded version
Good stuff right here
http://www.chevelles.com/forums/show...ighlight=kemco
Thing is I think it has lead in it so may affect cats if you have any.
Dont know if they have unleaded version
12-25-2015, 03:00 PM
#14
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I will take delivery of my 2016 C7 (with automatic transmission and Z51 package) next week in Belgium. The US manual calls for a fuel grade of 87 octane with 91 recommended. The Dutch version of that same manual calls for 95 octane with 97 recommended. I have always used (in my C5 and C6 Corvettes) the 95 octane grade. GM Europe is currently investigating this discrepancy and once I have their answer, I will let you all know. Merry Christmas ! Alex
12-25-2015, 05:13 PM
#15
Race Director
I will take delivery of my 2016 C7 (with automatic transmission and Z51 package) next week in Belgium. The US manual calls for a fuel grade of 87 octane with 91 recommended. The Dutch version of that same manual calls for 95 octane with 97 recommended. I have always used (in my C5 and C6 Corvettes) the 95 octane grade. GM Europe is currently investigating this discrepancy and once I have their answer, I will let you all know. Merry Christmas ! Alex
Not sure what GM Europe really has to investigate.
Different countries calculate octane ratings differently, so that explains why the difference between the US and European manuals.
https://en.wikipedia.org/wiki/Octane_rating
Research Octane Number (RON)
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)
Another type of octane rating, called Motor Octane Number (MON), is determined at 900 rpm engine speed instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern pump gasoline will be about 8 to 12 octane lower than the RON, but there is no direct link between RON and MON. Pump gasoline specifications typically require both a minimum RON and a minimum MON.
Anti-Knock Index (AKI) or (R+M)/2
In most countries, including Australia, New Zealand and all of those in Europe,[citation needed] the "headline" octane rating shown on the pump is the RON, but in Canada, the United States, Brazil, and some other countries, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2). It may also sometimes be called the Posted Octane Number (PON).
Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel.
The most common type of octane rating worldwide is the Research Octane Number (RON). RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane.
Motor Octane Number (MON)
Another type of octane rating, called Motor Octane Number (MON), is determined at 900 rpm engine speed instead of the 600 rpm for RON.[1] MON testing uses a similar test engine to that used in RON testing, but with a preheated fuel mixture, higher engine speed, and variable ignition timing to further stress the fuel's knock resistance. Depending on the composition of the fuel, the MON of a modern pump gasoline will be about 8 to 12 octane lower than the RON, but there is no direct link between RON and MON. Pump gasoline specifications typically require both a minimum RON and a minimum MON.
Anti-Knock Index (AKI) or (R+M)/2
In most countries, including Australia, New Zealand and all of those in Europe,[citation needed] the "headline" octane rating shown on the pump is the RON, but in Canada, the United States, Brazil, and some other countries, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2). It may also sometimes be called the Posted Octane Number (PON).
Because of the 8 to 12 octane number difference between RON and MON noted above, the AKI shown in Canada and the United States is 4 to 6 octane numbers lower than elsewhere in the world for the same fuel.
12-25-2015, 06:29 PM
#16
Drifting
No. When an octane booster says that it raises octane by "5 points" what they are not telling you is that a "point" is 0.1 compared to what is says on the pump. 5 points would be 0.5. As such running 87 with a 5 point octane booster would get you 87.5, hardly worth the money.
When I tried mine on 89 I was of the mindset that if I saw ANY timing retard at all, that I would stick with 93. Now could I run 89 or even 87? Sure I could but for me the cost difference really doesn't justify it. I've modified my car because I want horsepower, and I want that horsepower to be there and available all the time, not just when I happened to choose the right gas. Personally I can't see building a high performance car and then crippling it because of the fuel.
If the Vette is your only vehicle and you only ever drive Miss Daisy and you never press the go pedal for a little fun then sure, run the cheaper stuff and save a few (very few) $$. On the other hand if your Vette is more or less just a toy, and you know that every time you get in it there is at least the potential that you might want all the power it brings to the table, then go with the good stuff.
You can also look at fuel economy, what is your other option? In my case if I opted to take a road trip I could take a road trip in my F-150 or the Vette, F-150 gets about 18 best case on the highway, the Vette easily gets 25. Do the math, 600 mile road trip = 33 gallons in the F-150 vs 24 in the Vette. Say regular costs $4 a gallon and premium is $4.30. That = $132 to drive the F-150 and only $107.5 in the Vette. Personally I'd opt to take the fast one and use the more expensive fuel. Yeah it costs more but if I use less of it I'm still money ahead.
Maybe I'm just the odd one but I think I would rather find somewhere else to save the money. I mean think of it this way. Sure I could put regular gas in it, but then why do I bother with synthetic oil? Afterall if I'm not going to ever beat on it and get the oil hot, I might as well run regular right? But then if I'm never going to beat on it, why am I driving a Vette at all when I could just drive a Camry? I've just cheapskated myself out of a Corvette.
When I tried mine on 89 I was of the mindset that if I saw ANY timing retard at all, that I would stick with 93. Now could I run 89 or even 87? Sure I could but for me the cost difference really doesn't justify it. I've modified my car because I want horsepower, and I want that horsepower to be there and available all the time, not just when I happened to choose the right gas. Personally I can't see building a high performance car and then crippling it because of the fuel.
If the Vette is your only vehicle and you only ever drive Miss Daisy and you never press the go pedal for a little fun then sure, run the cheaper stuff and save a few (very few) $$. On the other hand if your Vette is more or less just a toy, and you know that every time you get in it there is at least the potential that you might want all the power it brings to the table, then go with the good stuff.
You can also look at fuel economy, what is your other option? In my case if I opted to take a road trip I could take a road trip in my F-150 or the Vette, F-150 gets about 18 best case on the highway, the Vette easily gets 25. Do the math, 600 mile road trip = 33 gallons in the F-150 vs 24 in the Vette. Say regular costs $4 a gallon and premium is $4.30. That = $132 to drive the F-150 and only $107.5 in the Vette. Personally I'd opt to take the fast one and use the more expensive fuel. Yeah it costs more but if I use less of it I'm still money ahead.
Maybe I'm just the odd one but I think I would rather find somewhere else to save the money. I mean think of it this way. Sure I could put regular gas in it, but then why do I bother with synthetic oil? Afterall if I'm not going to ever beat on it and get the oil hot, I might as well run regular right? But then if I'm never going to beat on it, why am I driving a Vette at all when I could just drive a Camry? I've just cheapskated myself out of a Corvette.
Its a performance car with the programming to take use of that 91 or greater octane. I use my GO pedal a LOT, I get ZERO spark retard at WOT all the time regardless of outside temps/engine temps,etc...why? I run 93 Sunoco.
Run 87 in your Camry this is a Corvette for crying out loud.
+1 I am one cheap bastard currently because of medical/financial issues. I cut corners everywhere with very few exceptions. Gasoline is one of them. I put in premium at a top tier gasoline retailer for the 'vette and regular top tier for the rest of the family vehicles (since that's what they call for). Most of the time I'm cruising with the wife but when I can get out alone, I like to mash the "GO" pedal. I changed the cam and when I had a tune done, it was found that I was getting a lot of knock retard. I had it tuned out and what a difference -
Why would I cheapen the fun, save a few bucks and drive like a granny to save the engine?
Save the money elsewhere.
And Merry Christmas
It's a Corvette dammit, have some fun.
Ah, hell I just saw this thread started over 3 1/2 years ago in 2012. Damn zombie threads get me every time when I have been drinking. Oh well, might as well have another drink.
Last edited by Silver96ce; 12-25-2015 at 06:33 PM. Reason: Damn zombie thread
12-25-2015, 06:40 PM
#17
Burning Brakes
I'm a bit of a penny pincher, but I still run premium in my Vette because its the recommended fuel by the manufacturer. Just because you "can" use lower doesn't mean you "should." Just my $0.02. Not that you'll be breaking anything running lower, but I drive a Vette in part because its a performance car, and I want it running at its best.
Honestly, the cost difference is very minimal.
Honestly, the cost difference is very minimal.
12-26-2015, 08:19 AM
#18
Drifting
According to Gordon Killebrew; the C4 guru from GM ... you are wasting money running premium.
(During a meet and greet seminar on the C4 during Corvettes of Carlisle a few years ago.)
(During a meet and greet seminar on the C4 during Corvettes of Carlisle a few years ago.)
Last edited by Bandit's C4; 12-26-2015 at 08:22 AM.
12-26-2015, 11:09 AM
#19
Le Mans Master
Member Since: Oct 2004
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Knock counts would tell the tale, or (especially better) degrees of spark retard. And, I'd be surprised if nobody here had some empirical data to refine the statement further...
12-27-2015, 06:15 AM
#20
Drifting
It shouldn't knock. The knock sensors should "detect" any knock before you can hear it, and retard the timing.
That is the reason for the statement in your owners manual about lower performance.
I wouldn't be doing any spirited or performance driving using regular grade though.
In a pinch (since that was all they had), I have used regular in my LT4. I didn't do any hard driving, and filled with premium on the next tank.
Didn't have any knocking issues, and since I was doing all interstate driving at the time my next fill up was the same day.
Bottom line though, it only costs a few dollars more per tank to use premium.
So, it's not like your going to save a fortune.
That is the reason for the statement in your owners manual about lower performance.
I wouldn't be doing any spirited or performance driving using regular grade though.
In a pinch (since that was all they had), I have used regular in my LT4. I didn't do any hard driving, and filled with premium on the next tank.
Didn't have any knocking issues, and since I was doing all interstate driving at the time my next fill up was the same day.
Bottom line though, it only costs a few dollars more per tank to use premium.
So, it's not like your going to save a fortune.
The knock is there or the knock sensor couldn't detect it. I agree a lot less but there. Sooo you are still doing some damage to the engine.
