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      03-03-2010, 12:00 PM   #3
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Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

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Originally Posted by TrackRat View Post
Increased octane only improves power if the engine management system is programmed to use the increased octane AND the engine actually needs the increased octane.

In regards to race fuels, octane is not the only consideration. Some race fuels achieve higher octane by using retardents. This does increase the octane but slows the burn rate. This type of fuel requires more ignition timing just to come close to a fast burn fuel of the proper octane.

There is a lot more to fuel and octane than what you typically find online. It's also worth noting that if the BUTT dyno was accurate we wouldn't use engine dynos, we'd just pull numbers out of our arse.
Information I have been given told me increased octane will actually add some power even if the engine management system and timing stay the same. This is because of the slower burn, allowing for the burn to continue for a longer period of the power stroke. Of course the difference is only minor and to take advantage you need an engine management system programmed for the higher octane. But typically the burn of fuel is long over before the power stroke has reached the bottom of it's travel, so the slower burning fuel helps to add some power. Any thoughts on this?