In the midst of my search for a Corvette, I've found a '96 Collector Edition with 70k, black interior (immaculate) really good paint and chrome ZR-1 wheels. The price is in my range and the seller will not budge on it (he is not a "vette guy" but he seems to know what he has and is not going to give it away).

The only problem is that he says that it runs fine on 87 octane! Now, I'm under the impression that that is the only grade he's put into the car! I know that you can get away with maybe one full tank of that stuff, but to run it constantly?

What I want to know is other than making the engine knock like a very determined Jehovah's Witness on a saturday morning, will this do any permenant engine damage? I really want this car, but I thought I'd see what you guys think. Never hurts to get a second opinion.

Thanks,
Michael

 

I don't think it will hurt anything except performance. The computer with the knock sensors makes up for the stupidity of some folks.

 

 

If you think about it 87 is only 4 points less than reccommended. Chevrolet only reccommends 91 octane. As for knocking, a faint pinging on hard acceleration or hills is not harmful, hard knocking is. Also if the car is not driven hard than it does not need maximum octane anyhow. i all comes down to, it's up to you dude.

 

It is perfectly fine to run 87 octane in your vette as long as you do not have a heavy right foot. If you drive it sanely... there will be no problems. Under the conditions that I drive... or others on this board... 87 octane would detinate and grenade the motor.

 

It should be fine until you floor it.

I would run the higher octane after purchase.

 

I would think that the knock sensor is perfectly capable of backing off the timing enough to prevent detonation even with spirited driving. I wouldn't worry about it. Just put in the good stuff and let the motor operate with better timing and you will have more power and better milage than he had.

 

In the manual - it states that you can use 87 in a pinch. I tried it once. The computer retards the hell out of the timing and you lose alot of power. The internals of the engine are probably fine - it just isn't as much fun to drive. If you can afford the car - you can afford the gas.

 

Amen brother!

 

With a typical $.20 per gallon difference bettween an 87 octane Regular grade and 91-92 octane Premium, that should be less than $4 a tank on a fill-up from empty.

Both my modded 87 and 92 cars will run on Regular, but there is a lot of pinging, even going up hills. Even the middle 89 octane stuff pings. Trying to run the car hard with a regular grade will decrease performance and may even risk detonation condtions.

Both The owner's manual and the message near the fuel filler state "Premium Fuel Recommended" on LT1 cars.

 

The ultimate stupidity of most people comes from buying fuel of a higher octane rating than what they need. The fact of the matter is that you want to run the LOWEST octane fuel you can without picking up any timing retard. If you can run full spark advance with no detonation on 87 octane then you are simply throwing money away by buying 89, 93, or 100 octane fuel. You're costing yourself horsepower AND money.

The idea that high octane fuel is "better" is complete crap. If you truly understand what gasoline ratings mean then you'll know what I'm saying is true. If you're like the majority of the public you'll argue till you're blue in the face with no facts to back it up.

To accurately determine what fuel your car needs, get the engine as hot as it's ever gonna be and run it in the hottest climate it is ever going to see. Then use some sort of logging software to determine if there is any knock detected and thus any corresponding timing retard at wide open throttle. If you see timing retard then you need to go up a grade in fuel. As soon as you find the octane rating that allows for zero timing retard under the most extreme conditions, STOP you've found your fuel. It's a tedious task that most people don't bother with.

 

All the gas comes out of the same tanker. 87 wont hurt the engine.
I use 91.

 

I know l98's can go fine on 89 and even 87 but since hte compression ratio on the lt cars are higher isn';t the 93 actually needed for good performance? it recommends 93 on my 95.

 

I don't run anything but 94 octane from Sunoco , on occasions if there is not one on a road trip I put 93 octane of whatever gas we stop for . A gas station attendant once put 89 oct in the car by mistake and a few days later my engine light went on ...here in Jersey your not allowed to pump your own gas ...

 

I think I'll be alright then, because the owner is an older gent, and I don't think he drove it "b**** to the wall" with it.

 

I have heard that before. Jersey has some issues

 

The octane rating that you run in your car was determined by the factory that produced your car. Running a higher octane than what is required will do nothing more for you car, but it will burn a deeper hole in your wallet. If the manual says to put in 87 octane, then that's what you should put in. Some people believe they are treating their car when they fill up with a higher octane than what is called for. The only people they are treating are the gas companies by freely and mistakingly giving them a present in the form of money.

The only time you should put a higher octane in your car than what the book calls for is when your engine has been modified, the compression has been raised or when the car needs the extra octane due to modifications. My car calls for 91 octane, but because I have heavily modified my car's engine and the compression is now 11:1, I need to put in a minimum of 93 octane. Anything less will cause excessive pinging. Even race fuel wouldn't hurt. This fuel run through a stock car could damage the engine. If you run excessively high octane in a vehicle (like race fuel) that hasn't been built for it, you can cause irreversible damage.

For novices reading this post, when you go into an auto parts store and see the cans of 100 or 110 octane racing fuel, DO NOT put them into your tank unless it is called for. You run the risk of burning your valves or causing other damage. For your car to run at peak effieiency, put in what is called for. In Corvettes, that is usually 91 octane. 93 or 94 octane won't do any harm, just don't go to 100 or higher.

 

not much choice of octane here in England we only have 93 or 98

 

I believe they rate it differently in Europe. Also understand that atmospheric conditions have a lot to do with it. For example you'd be very hard pressed to find 93 octane in Denver. The lower atmospheric pressure creates a lower octane requirement.

 

Oregon's the same way... I run 91 in my LT4, as that's the highest we can get here in CA w/o going to an airport...