[bobstan6]

Marathon Petro has a "recreational" fuel that is available in some locations, particularly marinas. It is No-Lead, 89-91 oct, and no alchohol. I hear some airports in Wisconsin are also dispensing it. I checked in the Tampa Bay area and 2 marinas have it for around $3.50 or so a gallon. Other Oil companies may also have the same thing.

Bob S.

 

[Paul PA]

I think you want at least 92-93 octane in the 912 of these planes due to their high compression.

 

[JohnF]

Alternate Fuel

That's interesting. The max octane you can get (outside of 100LL) at this altitude in Colorado is 91 octane...do I recall correctly? The actane ratings are varied in different parts of country based on altitude? Someone more knowledgeable than I can perhaps enlighten those of us who are 'unwashed.'

 

[Kyle Boatright]

That's interesting. The max octane you can get (outside of 100LL) at this altitude in Colorado is 91 octane...do I recall correctly? The actane ratings are varied in different parts of country based on altitude? Someone more knowledgeable than I can perhaps enlighten those of us who are 'unwashed.'

Yes, they do vary octane with altitude. Lower air pressure means a less dense charge and lower pressure on the compression stroke, so they can drop the octane without creating the risk of preignition.

I've seen what? 85 octane in higher-up areas - Colorado and such, wheras at my elevation (1,000'), I've never seen less than 87.

 

[the_other_dougreeves]

The 100Hp 912S that is in the -12 is speced for 91 octane (pump RON+MON) or better. The 80 Hp 912 (no "S") can use 87 octane.

TODR