What Octane rating do you use?
04-21-2014, 01:06 PM
#21
Do I need to explain what the Octane Rating means again?
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
04-21-2014, 01:28 PM
#22
Lucky me, the Happy Store on the corner is one of only two in town that sells Ethanol-free 93 octane, but at $4.36 a gallon (Middle Georgia area), it's quite pricey. I'll use it once a month and live with the other blends in between.
04-21-2014, 02:05 PM
#24
Team Owner
Same goes with other brands such as Conoco, Phillips 66, EXXON, etc.
Last edited by JoesC5; 04-21-2014 at 02:08 PM.
04-21-2014, 02:16 PM
#25
Do I need to explain what the Octane Rating means again?
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
You can play around with your car if you want but if you don't have a data logging system attached to your car you will never know if you are at the limits of the fuel simply by waiting for audible knock.
Don't over think this, simply use the highest octane rating that is prevalent in your area. You all will know what that is, it's either 93 or 91 octane.
In fact, areas that have 93 will have a mid grade at 89. It's very rare to see 91 and 93 available at the same station except for some pumps that blend the fuel between 2 tanks, an 87 and a 93/94 tank. Those pumps will blend 3, 4 or sometimes even 5 different grades. I stay away from those pumps, I don't trust them to be blending precisely enough or if I'm forced to use one I only use the lowest or highest grade, depending on the car I'm driving.
Last edited by mjw930; 04-21-2014 at 02:18 PM.
04-21-2014, 02:17 PM
#26
Do I need to explain what the Octane Rating means again?
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
The higher the Octane the higher the combustion temperature of the gasoline. That's it.
If you car is knocking then use higher octane. If it is not knocking then using a higher octane doesn't give you anything. Engine knock is the gasoline combusting too early and can cause damage.
Use what the manufacturer recommends...in this case 91. If the engine knocks then go to the next highest. You're just wasting your money buying 93 octane if the cars runs fine on 91.
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rb185afm (08-24-2018)
04-21-2014, 05:07 PM
#28
Team Owner
In my case, GM says to use nothing below 91 octane but 93 octane is what GM recommends for my C6 Z06(as well as the ZR1). Thus, 93 E10 will give me the best performance but at the loss of fuel mileage. Fortunately, I am able to get 93 zero ethanol free gasoline locally, so I get the best of both worlds.
04-22-2014, 05:29 AM
#30
That is almost, but not quite correct. There are two octane rating methods, research and motor, abbreviated R and M. The R number is about 10 higher than the M number, but it can vary a bit, in the range of 8-11 higher. The US and Canada use the formula (R+M)/2 to post the octane number on their pumps, while Europe and the Middle East use just the R number. Since R is 8-11 higher than M, then R is 4-5 higher than (R+M)/2. So if you are in Europe or the Middle East and see pump postings of 91, 94, or 98, those are in “R number”, and are equivalent to US or Canada postings of 87, 89, or 93 in “(R+M)/2 number”.
Mixing them will just lower the octane of the higher one. In the United States the refineries just make the high octane and low octane grades and mix them (most times at the service station) to give the consumer the mid-grade if he chooses.
We have many great comments on this thread from knowledgeable people. That said, I'd like to point out that LDB has long posted on the C6 forum regarding gasoline and is a recognized expert as he has extensive experience in upper management in the gas industry. He gives unbiased, easy to understand information. If you would like to learn about gasoline and what might be best for your car, I would suggest doing a search under his name for his previous posts.
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beaversstonehaven (08-24-2018)
04-22-2014, 06:27 AM
#31
Pro
Have seen several C6's there on past visits.
08-23-2018, 07:37 PM
#32
1st Gear
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Higher octane only prevents engine knock due to compression ignition
The LT1 engine requires premium but you could use 89 or 87 octane if premium were not available. The engine won't have the power that premium provides but it will run until premium fuel can be found. That's not an issue for you so your C7 will be fine with 91 or 95 octane. You can mix them up with no problem. The 98 octane you have access to probably won't do anything more for the engine but someone with track experience may have another opinion.
I use 93 octane and my Stingray run fine.
I use 93 octane and my Stingray run fine.
of the fuel-air mixture due to compression which causes engine knocking. I have an 08 Harley Davidson Ultra touring motorcycle which also requires high octane but I have always used regular gas and have never had any issues due to engine knocking.
Last edited by Jesse Perez; 08-23-2018 at 07:39 PM. Reason: Typo
08-23-2018, 08:44 PM
#33
I use 93 octane. Shell and Shell only.
08-23-2018, 10:28 PM
#35
2017 Owner's Manual approved grades.
08-23-2018, 11:15 PM
#36
Moderator
Mobil 93.
08-23-2018, 11:18 PM
#37
The LT1 engine requires premium but you could use 89 or 87 octane if premium were not available. The engine won't have the power that premium provides but it will run until premium fuel can be found. That's not an issue for you so your C7 will be fine with 91 or 95 octane. You can mix them up with no problem. The 98 octane you have access to probably won't do anything more for the engine but someone with track experience may have another opinion.
I use 93 octane and my Stingray run fine.
I use 93 octane and my Stingray run fine.
08-24-2018, 07:28 AM
#40
Racer
I ran several tanks of 89 octane and couldn't tell any difference. I take it pretty easy on my driving though. Is it worth the $5 difference in fills? I'm still undecided.