regular gas
Drifting
Joined: Apr 2005
Posts: 1,746
Likes: 0
From: Upper St. Clair PA
St. Jude Donor '06-'07-'09
Gasoline Octane
Use premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also use
middle grade or regular unleaded gasoline rated at 87
octane or higher, but your vehicle’s acceleration may be
slightly reduced. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
Would somebody explain where this manufacturer's recommendation says that Regular 87 will harm your engine? IT DOES NOT! The only effect is that "acceleration may be slightly reduced." I think GM engineers know more about this engine and it's operational characteristics than this group of worry warts.
Use premium unleaded gasoline with a posted octane of
91 or higher for best performance. You may also use
middle grade or regular unleaded gasoline rated at 87
octane or higher, but your vehicle’s acceleration may be
slightly reduced. If the octane is less than 87, you may
get a heavy knocking noise when you drive. If this occurs,
use a gasoline rated at 87 octane or higher as soon as
possible. Otherwise, you might damage your engine.
Would somebody explain where this manufacturer's recommendation says that Regular 87 will harm your engine? IT DOES NOT! The only effect is that "acceleration may be slightly reduced." I think GM engineers know more about this engine and it's operational characteristics than this group of worry warts.
That said, I am looking for top-notched street cruising with no combustion chamber varnishing. So I only use high octane gas.To the OP: No how, no way!
Race Director
Joined: Dec 2007
Posts: 19,574
Likes: 167
From: Frederick, MD
I don't think I'd run the 87 octane... the 89, ok, that's what I'm running now.
From Click and Clack:
"Use the grade of gas you need and nothing higher.
Does your owner's manual say "Premium Unleaded Only"? No? Then don't ever use premium fuel. There. We just saved you 40 cents a gallon... or $8 on a 20-gallon fill up. If your engine is designed to run on regular gas, there's absolutely no benefit to putting in "high test." It pollutes more, it costs more, and doesn't give you any benefit in performance or fuel system cleanliness.
Now, what if your car DOES call for minimum 91 octane? Well, next time you buy a car, dumkoff, check what kind of fuel it requires first. We've always said that once you buy the car, you're stuck. You've got to use 91, because your high compression engine will ping if you don't. But now, most cars have "knock sensors," that retard the timing via the engine management computer (effectively lowering the compression) to protect the engine, in the event that you happen to get some bad gas, or have an emergency and can only get regular grade fuel. So we got to thinking, what would be wrong with using the knock sensor all the time? What if you put regular gas in the car all the time and let the knock sensor do its job and retard the timing? You'd have a little less power, but that extra 8 bucks a fill up might be more important to you than power right now. It would be to us.
It's a controversial theory, we admit it. But that's never bothered us before. And we can't think of any long-term effects of driving with the knock sensor retarding the timing. So our position (for the time being) is... use regular. Who cares? Now, if there are any actual automotive engineers in the audience who have worked on knock sensors, who want to tell us why we have our heads up our keisters, feel free to write to us. And if we're convinced that we're wrong, we'll happily change our recommendation."
From Click and Clack:
"Use the grade of gas you need and nothing higher.
Does your owner's manual say "Premium Unleaded Only"? No? Then don't ever use premium fuel. There. We just saved you 40 cents a gallon... or $8 on a 20-gallon fill up. If your engine is designed to run on regular gas, there's absolutely no benefit to putting in "high test." It pollutes more, it costs more, and doesn't give you any benefit in performance or fuel system cleanliness.
Now, what if your car DOES call for minimum 91 octane? Well, next time you buy a car, dumkoff, check what kind of fuel it requires first. We've always said that once you buy the car, you're stuck. You've got to use 91, because your high compression engine will ping if you don't. But now, most cars have "knock sensors," that retard the timing via the engine management computer (effectively lowering the compression) to protect the engine, in the event that you happen to get some bad gas, or have an emergency and can only get regular grade fuel. So we got to thinking, what would be wrong with using the knock sensor all the time? What if you put regular gas in the car all the time and let the knock sensor do its job and retard the timing? You'd have a little less power, but that extra 8 bucks a fill up might be more important to you than power right now. It would be to us.
It's a controversial theory, we admit it. But that's never bothered us before. And we can't think of any long-term effects of driving with the knock sensor retarding the timing. So our position (for the time being) is... use regular. Who cares? Now, if there are any actual automotive engineers in the audience who have worked on knock sensors, who want to tell us why we have our heads up our keisters, feel free to write to us. And if we're convinced that we're wrong, we'll happily change our recommendation."
Second paragraph summary. Yes knock sensors will retard your timing which affects your gas mileage and performance negatively. You can be a cheapo if you want to but you shouldn't have bought a high performance car in the first place since you are willing to degrade its performance.
Third paragraph summary. They obviously never cruised up Parley's Summit which is a 4000 foot climb in about 10 miles. At 75mph the Vette is turning a relaxed 1700rpm. Just throw the crappy gas in there and let the knock sensors do their job. It'll still survive the warranty.
People need to consider the price of premium when they buy the car, especially a high performance car. The "savings" may buy you lunch every 3-4 weeks.
I wouldn't sweat it if the wife puts in 87 by mistake but I wouldn't do it on purpose unless it is the only gas around.
Safety Car
Joined: Feb 2007
Posts: 4,939
Likes: 448
From: CHOCOWINITY NC
Le Mans Master
Joined: Jan 2004
Posts: 6,897
Likes: 181
From: Menifee (I.E.) CA
Let's see, what are some of the things people want to do without consulting the owners manual...
1) Can I do my oil change at 3K?
2) Can I use another oil?
3) Can I use a lesser octane fuel?
4) Can I inflate my tires to what I want?
And the list goes on and on and on and on...
1) Can I do my oil change at 3K?
2) Can I use another oil?
3) Can I use a lesser octane fuel?
4) Can I inflate my tires to what I want?
And the list goes on and on and on and on...
Team Owner
Joined: Mar 2008
Posts: 21,502
Likes: 461
From: Southern Utah
Or.....because its a $50-$70K car, you must always choose the more expensive option when given a choice.....otherwise someone on the forum will tell you that you should have gone with the more expensive choice...
And yet people here always complain about the Corvette tax. The Corvette tax survives because many people here like to pay more for anything Corvette related. The tax helps them do that and feel good about whatever they bought...because it was more expensive...
And yet people here always complain about the Corvette tax. The Corvette tax survives because many people here like to pay more for anything Corvette related. The tax helps them do that and feel good about whatever they bought...because it was more expensive...
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Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
that is not how it works because once the computer detect a spark knock the timing stays retarded till you refill the tank. the computer assumes you have a tank full of bad gas and will retard the ignition timing till you refill the tank.
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
On the other hand, if the injectors get clogged up, wouldn't chunking some Sine-x in the tank solve the problem ? Uh-oh, that might cause excess post tail pipe drip.
Race Director
Joined: Jul 2004
Posts: 16,795
Likes: 62
From: Lake Havasu City, AZ
If you drive like my grandmother did, there will be no issues.
It took here at least a minute to get up to 30 mph....
If you drive like my wife...who has 410's in the rear of her C5, then you will be getting engine knock because the computer can't retard the timing enough...
IT just depends on how you drive...
It took here at least a minute to get up to 30 mph....
If you drive like my wife...who has 410's in the rear of her C5, then you will be getting engine knock because the computer can't retard the timing enough...
IT just depends on how you drive...
Team Owner
Joined: Sep 2005
Posts: 29,113
Likes: 2,194
From: Big Bend Country, TX
St. Jude Donor '06-'07-'08-'09-'10-'11-'12-'13-'14-'15- '16-'17-‘18-‘19-'20-'21
NCM Lifetime Member
Instructor
Joined: Feb 2005
Posts: 238
Likes: 0
From: Michigan
If you drive like my grandmother did, there will be no issues.
It took here at least a minute to get up to 30 mph....
If you drive like my wife...who has 410's in the rear of her C5, then you will be getting engine knock because the computer can't retard the timing enough...
IT just depends on how you drive...
It took here at least a minute to get up to 30 mph....
If you drive like my wife...who has 410's in the rear of her C5, then you will be getting engine knock because the computer can't retard the timing enough...
IT just depends on how you drive...
I resemble that remark !
Burning Brakes
Joined: Nov 2007
Posts: 1,002
Likes: 0
From: Virginia Beach VA
What the heck does the octane have to do with "varnish?" The answer is "nothing." Detergents in the gasoline's additives are there to help keep fuel system clean, not the octane level. In some cases you may get more detergents when you increase the grade of fuel.
Melting Slicks
Joined: May 2007
Posts: 2,415
Likes: 154
your last statement is correct and the additives are put in by the local distributor so he could cheat to make more profit so i would stick with a national brand gasoline not a no name. GM one time threatened to list the brands of gasoline with the proper additive in the owners manual of their cars if all brands did not have the proper additives as it was costing GM lots of $$$$ to replace injectors under warranty