Fuel choices
Road Warrior
Joined: Sep 2010
Posts: 1,260
Likes: 44
From: Back woods of Maine
Don't think that I've seen anything BUT ethanol gas up here anywhere for a very long time.
Banned
Joined: Feb 2011
Posts: 119
Likes: 0
From: Home
Tourer
Joined: Aug 2010
Posts: 314
Likes: 7
From: Greeley Colorado
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Extreme HDF Member
Joined: Dec 2007
Posts: 13,402
Likes: 941
From: Illinois
I have three TC96's an 07 FXSTC, 10 Ultra and a 10 Dyna SG. I have stage I intake, HD oil cooler and the Fi2000r Cobra programmer on all of them. Until this year, I ran 89 without any issues.
This year on a 6,000 mile ride to the mountains then Death Valley and the desert SW, I decided to try 87.
The Ultra ran strong in 6th from 55 mph on the flat to 70 up steep grades in the Rockies. Averaged 45 + mpg. No pinging whatsoever.
HD "recommends" 91. The reason that they don't say must use is that the Fed's require that the motors must be able to run on 87 octane.
So with three TC96's with 5.5 years of in service and about 30K miles between them one can not argue with success.
By the way HD service manuals do say "DO NOT" use octane boosters or racing fuel.
The ECM can only tune the motor for 91 octane so more is a waste.
Also, the lower the octane the more complete it burns. All gas is not fully burned and some goes out the exhaust pipe. So the opposite from what a few posted is true. 87 to 90 octane will improve mpg a little. Missouri is different that any state I went through. The pumps have five choices. 91,90,89,88 and 87.
This year on a 6,000 mile ride to the mountains then Death Valley and the desert SW, I decided to try 87.
The Ultra ran strong in 6th from 55 mph on the flat to 70 up steep grades in the Rockies. Averaged 45 + mpg. No pinging whatsoever.
HD "recommends" 91. The reason that they don't say must use is that the Fed's require that the motors must be able to run on 87 octane.
So with three TC96's with 5.5 years of in service and about 30K miles between them one can not argue with success.
By the way HD service manuals do say "DO NOT" use octane boosters or racing fuel.
The ECM can only tune the motor for 91 octane so more is a waste.
Also, the lower the octane the more complete it burns. All gas is not fully burned and some goes out the exhaust pipe. So the opposite from what a few posted is true. 87 to 90 octane will improve mpg a little. Missouri is different that any state I went through. The pumps have five choices. 91,90,89,88 and 87.
Last edited by lh4x4; Jul 12, 2011 at 08:47 PM.
Road Warrior
Joined: Apr 2011
Posts: 1,905
Likes: 66
From: Hartford, AL
Been running 87 for a few tank fulls and getting 2-3 mpg better, no pinging under any load and no hotter. Maybe if the intake and exhaust were stock it would be different. I don't believe everything HD or the government tells me.