I read the 2nd post (Mercury take on ethanol blended fuel) first it says, go by the octane rating, then said, it might drop as much as 3 points. I live up north, everything has 10% in it. Running a 08 175 opti. Mercury says to run 87 octane. Should I or could I run a higher octane than 87??
Moving up to 89 octane would be acceptable (mid-grade). I would not, however, recommend anything higher than 89 octane.
Running too high an octane can actually COST you in performance, and can contribute to Carbon Buildup. Higher Octane fuels burn "slower and cooler".
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
I have a 87 Mercury 150, v6, ser # 6617258. I live in Southern California and the local boat mechanic told me to only run the 92 premium. Should I be running a lower octane fuel instead?
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by seance »</td></tr><tr><td class="quote">I have a 87 Mercury 150, v6, ser # 6617258. I live in Southern California and the local boat mechanic told me to only run the 92 premium. Should I be running a lower octane fuel instead?</td></tr></table>
VERY different engine. The main question would be WHY your mechanic made this recommendation. It may be based on the engine's COMPRESSION.
Do you know what your compression numbers are?
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
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by EuropeanAM »</td></tr><tr><td class="quote">Moving up to 89 octane would be acceptable (mid-grade). I would not, however, recommend anything higher than 89 octane.
Running too high an octane can actually COST you in performance, and can contribute to Carbon Buildup. Higher Octane fuels burn "slower and cooler".
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Don,
I too live up north and have recently read several posts on different sites that claim that you cannot always be guaranteed that the ethanol blend at the station is only 10%. The only non-oxy gas I've been able to find anywhere around home is 91 octane.
Given the above, which would be less risky for my engine (2001 175 EFI)? 87 octane with an unpredictable percentage of ethanol or non-oxy 91 octane with maybe Quickleen (or some equivalent) that would control carbon build-up?
"There was a time I didn't fish, but I cannot remember it".
Don, you asked "Do you know what your compression numbers are?"
all cyls are 126 - 130psi
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by seance »</td></tr><tr><td class="quote">Don, you asked "Do you know what your compression numbers are?"
all cyls are 126 - 130psi</td></tr></table>
Your engine might benefit from 89 octane (mid-grade) fuel... but should NOT require high-test (any higher than 89 octane).
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
<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by Macsimus »</td></tr><tr><td class="quote">
Don,
I too live up north and have recently read several posts on different sites that claim that you cannot always be guaranteed that the ethanol blend at the station is only 10%. The only non-oxy gas I've been able to find anywhere around home is 91 octane.
Given the above, which would be less risky for my engine (2001 175 EFI)? 87 octane with an unpredictable percentage of ethanol or non-oxy 91 octane with maybe Quickleen (or some equivalent) that would control carbon build-up?
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I recommend choosing your fuel on the following criteria, IN THE FOLLOWING ORDER (Specifically):
-Your engine's RECOMMENDED Fuel Octane. Where possible, utilize the RECOMMENDED octane level.
-Name Brand, well known fuel with HIGH TRAFFIC station. The "turnover and traffic level" of the station. Higher traffic stations tend to have FRESHER fuel.
-Ethanol content. The lower the better, but NEVER more than 10%. Inexpensive ethanol testers are available (we carry them) that you can utilize to field test fuel, just to see if you're being "fed a line".
http://www.bbcboards.net/zerot...-have
Given the choice between 91 octane "non-ethanol" and 87 octane that contained 4-7% ethanol, I'd choose the appropriate octane fuel.
Of course, I'd also make sure that my boat's fuel system was properly upgraded, as well.
http://www.bbcboards.net/zerot...first
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
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