Interesting find regarding octane index....
Thread Starter
Instructor
Joined: May 2001
Posts: 238
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From: Conifer CO
Interesting find regarding octane index....
Some time back, I requested and received from Chevy free data about the 1999 Corvette. Included were some 35 pages of "Manufacturers Motor Vehicle Specifications". On page 3 under Engine- General for Fuel antiknock index (R+M)/2 Chevrolet lists 87.
Not 91 or 92, but 87.
Down below there is a posting from someone who used 89 octane instead of 91, with good results. Most of the replies to that posting agree with him.
I know what the manual says, but the MVMA says 87.
There are two ways to express a gasolines octane number. Actually 3)
RON means Research Octane Number. MON is for Motor Octane Number. What we see on the pumps is the sum of those two, divided by two, or (R+M)/2
For what it's worth, I am switching to 87 octane, which at my altitude (8800') and therefore cooler temperatures, should work just fine. During the winter I could probably use regular up here!
Not 91 or 92, but 87.
Down below there is a posting from someone who used 89 octane instead of 91, with good results. Most of the replies to that posting agree with him.
I know what the manual says, but the MVMA says 87.
There are two ways to express a gasolines octane number. Actually 3)
RON means Research Octane Number. MON is for Motor Octane Number. What we see on the pumps is the sum of those two, divided by two, or (R+M)/2
For what it's worth, I am switching to 87 octane, which at my altitude (8800') and therefore cooler temperatures, should work just fine. During the winter I could probably use regular up here!
Safety Car
Joined: Mar 2002
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Cruise-In V Veteran
St. Jude Donor '09
Re: Interesting find regarding octane index.... (RWhite)
R White - here's an interesting thread on Octane tables http://www.efilive.com/forum/viewtopic.php?t=282 FWIW.
Team Owner
Joined: Apr 2001
Posts: 54,204
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From: S.W. Ohio. . . . . . NRA Life Member
Re: Interesting find regarding octane index.... (RWhite)
On page 3 under Engine- General for Fuel antiknock index (R+M)/2 Chevrolet lists 87.
Not 91 or 92, but 87.
Not 91 or 92, but 87.
Before computer controlled engines... octane below the optimum engine tuning could cause problems. 87 octane will not damage the LS1, but the PCM will detune the engine to compensate.
Why buy a sports car... and then intentionally reduce the engines power output ???
Melting Slicks
Joined: Oct 2003
Posts: 2,655
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From: Brea CA
Re: Interesting find regarding octane index.... (Colorado Chuck)
Good Point... and I just got an idea from a certified mechanic... he tells me that what ever octane gives the best gas mileage will also be the one that gives you the most power... So if you make the same drive, under the same conditions, with cruise control on... you can see which works better........
:party: :steering: :auto: :hurray: :chevy :cheers: :eek: :skep: :leaving:
:party: :steering: :auto: :hurray: :chevy :cheers: :eek: :skep: :leaving:
