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

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.

When I had the LT1 I ran mid grade all the time, except for track days, and never had any problem. Still plenty of performance and never got a knock code.

I data logged my fairly well modified LT1 while running 89 octane. On a really hot night with the AC on I got like 1 degree of retard. Stock should be fine.

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.

Does adding a octane booster to regular 87 make up the difference? Where I live premium includes ethanol, not sure if that is good to run either?

We've been running Mid-grade in our LT4 for bout 5-6 yr now and never had a problem.Still as peppy as ever....

Ethanol is a fact of life in many areas, like here in iL, and we get along with it just fine...for the most part. There IS some legitimate concern, as far as at least some fuel injectors made before 1993 go. So, if it were me, I'd change the injectors to new stainless units (NOT NOS injectors, BTW), and not worry about alcohol OR so-called "octane boosters".

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:eek:). 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.

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.

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. :smash:

:iagree:

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. :thumbs:

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.

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

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

Since your talking about a C7, you probably should have posted in that section instead of the C4 section.

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

^^^^^^^^^^:iagree: +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 -:woohoo:
Why would I cheapen the fun, save a few bucks and drive like a granny to save the engine?

Save the money elsewhere.
:cheers:
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.

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.

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.)

I wonder in what context he made that remark; e.g., low throttle vs. heavy throttle (for one). Also, there were 5 different engines with compression ratios ranging from 9.0 to 11.0; 2-valve, wedge vs. 4-valve, pent-roof chambers. And, with that, red line rpm ranged from ~ 4200 to 7100 rpm.

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...:yesnod:

:iagree:

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.