Regular or Premium gas?
07-31-2011 | 02:53 PM
#21
Gold Member
Joined: Jun 2009
Posts: 168
Likes: 0
From: Williamsburg, MI
All I have gotton from running higher octane than 87 is added soot on the back of the boat, I will put some 91 the first tank of the season to add to last years fuel to compensate for octane loss from sitting.
08-02-2011 | 07:41 PM
#22
Registered
Joined: Feb 2005
Posts: 4,400
Likes: 25
From: Michigan
I may have the wrong motor. I think this motor runs slower with 93 then 87. The ecm would run the motor just before detonation. With 93 the ecm would not see any sign of detonation from the knock sensor and would think the knock sensor was bad, and run with reduce timing, thus giving less performance that 87 octane.
08-02-2011 | 08:43 PM
#23
Registered
Joined: Sep 2001
Posts: 2,287
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From: Houston, TX, USA
Motor was a 454, not sure what year this was a problem but yes. ECM ran the timing on the verge of detonation. When it thought it should see detonation and did not, it backed the timing way up.
08-02-2011 | 10:15 PM
#25
Charter Member # 55
Joined: Oct 2000
Posts: 20,264
Likes: 2,509
From: Omaha/LOTO
All higher octane will do is make your transom sooty from not burning as completely.
