2018 115 Pro XS - OIL, the great debate, and what fuel?

emilime75

Petty Officer 1st Class
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Jun 23, 2009
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204
Just bought this 4 stroke last night and want to change the oil and filter before I take it out.
I know this is a topic that gets discussed a lot...but I'll ask it anyway, what oil? 10W30 or 25W40? Synthetic or dino? It'll never be used in temps below about 50 and higher than about 100 degrees ambient. This is my 1st outboard, only had I/Os before.
Beyond that, what fuel? 89 E10 OK, or does it have to be ethanol free?
 

Alumarine

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Feb 22, 2005
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3,738
The sticker on the motor suggests the 25W-40 FC-W is better for hotter temps so I'd go with that.
Maybe split the difference and use Semi-Synthetic?
 
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emilime75

Petty Officer 1st Class
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Jun 23, 2009
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I've seen people say that on forums, which is why I'm asking. The sticker on my engine only lists 10W30 FC(W) with a 0-120 degree temp range. Thought I'd just stick with that, but I can't find it locally, only the 25W40...if I'm sticking to "marine" oil.
 

Alumarine

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Feb 22, 2005
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My bad then.
I thought the recommended was 25W-40 with the 10W-30 as an alternate.
What's the serial number?
 

Alumarine

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Feb 22, 2005
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They've changed it from what I was familiar with.
It used to be the opposite. Not sure of their reasoning.

Engine Oil Recommendations
Mercury or Quicksilver NMMA FC‑W or NMMA FC‑W catalyst compatible
certified SAE 10W‑30 4‑Stroke Marine Engine Oil is recommended for general,
all‑temperature use. As optional choices, Mercury or Quicksilver NMMA FC‑W
SAE 25W‑40 Mineral Marine 4‑Stroke Engine Oil or SAE 25‑W40 Synthetic
Blend Marine 4‑Stroke Engine Oil may be used. If the recommended Mercury
or Quicksilver NMMA FC‑W certified oils are not available, a major outboard
manufacturer's brand of NMMA FC‑W certified 4‑Stroke outboard oil of similar
viscosity may be used.
 

emilime75

Petty Officer 1st Class
Joined
Jun 23, 2009
Messages
204
It looks like my local Academy Sports has the QuickSilver 10W-30. Anyone see a problem with going mostly 10W30, but topping off the last 2 quarts with QuickSilver 25W40 Synth blend? I've got some left over from my previous boat.
 
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