9.9 merc bigfoot

[markmwm]

in a 2002 merc 9.9 bigfoot what is the best octane of fuel to use. and should we ever use 10% metanol, or stabilizer or octane boost. Thanx

 

[ZmOz]

Re: 9.9 merc bigfoot

87 octane. Anything more is throwing your money in the toilet. No, you should never use 10% METHANOL in any gasoline engine...but 10% ETHANOL like they sell at the pumps is fine.