What grade of gas

[Lowerider58]

Ethanol actually is a very good, clean burning fuel. It has a very high equivalent octane rating in the 110+ range. The down side is our engines are not set up to burn ethanol. If we had high compression engines (cranking compression of 220PSI+) and all of the fuel lines and related equipment was compatible It would be excellent. But, we don't. Some of the cons are the problems with storage and transport. Also it contains about 60% as much energy as an equivalent amount of gasoline.
My feeling is why are we burning our food stock in our combustion engines when we are awash with petroleum? Also due to the decrease energy content, if gasoline was $2 a gallon then ethanol would need to be about $1.20 a gallon.

It's because of the farm lobby shoving it down our throats.

[gehol]

You are correct along with the big ethanol producers.

[DustyD26]

Yep, i'm always confused why guys will pay more for 91 non ethanol. Run the octane the motor is designed for. Ethanol is not the boogie man some make it out to be.

I disagree. It depends what your motor is. In a carbureted 60deg motor like my 2001 Johnson it is the Boggie man. In these new motor that have been designed to run gas containing ethanol not so much. But in mine the ethanol warps the bowls and all kinda bad stuff.

[granite]

I decided to go check the Mercury website ( http://www.mercurymarine.staging.yar...outboards.aspx ) for information, was suprised that they recommend 91 octane in almost all of their motors/engines, with exceptions:

MERCURY & MARINER FUEL RECOMMENDATIONS

• Use a major brand of automotive unleaded petrol (ULP) with a minimum posted octane rating of 91
• These recommendations apply to Mercury and Mariner 2-Stroke, 4-Stroke, Verado and OptiMax models unless specified otherwise (ref to "Notes & Exceptions" following)

Notes & Exceptions
Verado Models:

• Verado 275/300hp - Premium Unleaded Petrol with a minimum 95 octane recommended for maximum performance
• Verado 350hp - Premium Unleaded Petrol with a minimum 95 Octane Recommended for Maximum performance
• Verado 400R - Premium Unleaded Petrol with a minimum 98 octane

Engines manufactured prior to 1980:

• 2hp to 20hp - Unleaded Petrol (ULP) - minimum 91 Posted Octane
• 30hp & above - Premium Unleaded Petrol (PULP) - minimum 95 Posted Octane

[gehol]

I am going to guess this is not for American engines but, perhaps Canadian. I think Canada uses RON numbers where here it is the average of RON and MON.

[granite]

I am going to guess this is not for American engines but, perhaps Canadian. I think Canada uses RON numbers where here it is the average of RON and MON.

Wouldn't the Mercury website state something to that effect? Appears to be a US website with no mention of RON or MON. Not trying to stir the pot, just trying to get some clarity on a subject that everybody seems to have an "opinion" on. Thanks.

[Cerus]

If that’s the case they’ve changed it since I bought my boat last year with a 60 on it. My manual says 87 MINIMUM.

[Casslaw]

I think the Mercury notations that are above aren’t for the US. We don’t use the word Petrol. Maybe Great Britain or somewhere else, but most of US say gasoline or petroleum.

Everything I read in the Evinrude site for the Etec & the G2 from my 90 to the 300 say minimum 87 with no mention of ethanol.

With an older carb’d motor I wouldn’t use a fuel with any ethanol in it, period. But that’s me.

[RFSims]

87AKI=91RON