.... But they only have it in 91 octane -- Is this OK for my '09 225 Opti? I think it's supposed to run 89 max - but which it better - 91 with no ethonol or 87/89 with corn syrup in it
Modified by Gunnar at 8:31 AM 3/9/2011
.... But they only have it in 91 octane -- Is this OK for my '09 225 Opti? I think it's supposed to run 89 max - but which it better - 91 with no ethonol or 87/89 with corn syrup in it
Modified by Gunnar at 8:31 AM 3/9/2011
I think your opti is to run on 87 octane you can run the 91 but make sure you run mercury quickleen in the recommended amount when you add gas, your motor doesn't have the compression to run higher octane, and you won't burn the gas as efficient as a high compression motor, in turn you will get alot of carbon, I would opt for the 87 octane and add quickleen and startron for the ethanol. I went to a training seminar years ago about fuel when I worked at the motorcyle shop, and the higher the octane the cooler and slower burning the flame is that's what keeps higher compression engines from detonation IE. race motors 87 is easier to ignite thats why in hotter engines with high compression you get what you call spark knock, the fuel trys to ignite before the piston reaches top dead center... higher octane stops the detonation.....
When I'm presented with a similar choice.... I'll opt for 87 octane with less than 10% ethanol content EVERY time.
Higher octane fuels burn SLOWER AND COOLER (meaning an incomplete burn).... and can produce increased amounts of carbon (not to mention, they cost more, and perform LESS).
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 48 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Reply With Quote