View Poll Results: Which octane fuel do you use?
87 octane (regular)
44
23.78%
89/90 octane (plus)
27
14.59%
92/93 octane (super)
97
52.43%
AV/ other or Allan 4 is a putz
17
9.19%
Voters: 185. You may not vote on this poll
Which octane fuel do you use?
04-11-2005 | 06:38 PM
#21
A to Z
Joined: Apr 2004
Posts: 9,156
Likes: 2
From: KC/LOTO
Re: Which octane fuel do you use?
Originally Posted by Bigyellowcat
called my motor guy and he said it would not drop to that low of hp to set it up to run on 87
04-11-2005 | 07:38 PM
#24
Registered
Joined: Feb 2001
Posts: 1,849
Likes: 1
From: charlotte nc.
Re: Which octane fuel do you use?
93 for me and i know all of you are getting ready to drag the boats out just remember the old gas in the tank will not be as high octain as it was in the fall might wont to put some additive in and run it easy to you can get some of the old fuel out and some good in 
04-11-2005 | 08:08 PM
#26
Registered
Joined: Mar 2003
Posts: 3,073
Likes: 79
From: Fort Worth, TX
Re: Which octane fuel do you use?
you guys running 87-89 in 500's...what temp are you running in and how hard?
This will be the first season for me with 572ci 650's, I plan to run 93. I always ran 93 with 425's too.
This will be the first season for me with 572ci 650's, I plan to run 93. I always ran 93 with 425's too.
04-11-2005 | 08:25 PM
#28
Masher touches my
Joined: Aug 2004
Posts: 2,280
Likes: 0
From: Phoenix, Az
Re: Which octane fuel do you use?
I always ran 87 in my 502 mag mpi with no problem or excess soot on the transom. When I put the Vortech Supercharger on the knock sensor kicks in around 5100 rpm even with premuim gas, so I run A/V gas now with no problems. All Merc motors are designed to run off 87 octane just like every one is saying in the thread. Dont waste your money on anything else, it won't make a diferrence. I do believe that Chevron with Techroline is good on your injectors though. Its supposed to help especially with Gm injectors wich are known for clogging and failing. 
04-11-2005 | 08:26 PM
#29
Registered
Joined: Aug 2002
Posts: 2,896
Likes: 3
From: Eastern Lake Ontario
Re: Which octane fuel do you use?
It's just amazing how many people, even supposed motor-heads, have no clue what the real function of octane is. All you need to do is read a little and get the real scoop.
Compression, compression, compression. If you don't run a high compression engine, you don't need high octane. Octane prevents pre-ignition caused by compression. In a higher compression engine, the fuel/air may (will) explode under compression before the piston reaches the top of it's stroke. Imagine the stresses when that happens. That little "knock" you here is your piston being jammed back down on it's up-stroke. Not good! However, as many have stated above, if you don't need it, don't spend the money on it.
Compression, compression, compression. If you don't run a high compression engine, you don't need high octane. Octane prevents pre-ignition caused by compression. In a higher compression engine, the fuel/air may (will) explode under compression before the piston reaches the top of it's stroke. Imagine the stresses when that happens. That little "knock" you here is your piston being jammed back down on it's up-stroke. Not good! However, as many have stated above, if you don't need it, don't spend the money on it.
04-11-2005 | 08:34 PM
#30
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Joined: Jul 2004
Posts: 1,853
Likes: 1
From: atlantic city, NJ
Re: Which octane fuel do you use?
Originally Posted by Bigyellowcat
called my motor guy and he said it would not drop to that low of hp to set it up to run on 87
