I have a 2016 mercury optimal pro XS. I’ve been told to run all different octanes and was wondering if you guys knew what was best..
thank you!
I have a 2016 mercury optimal pro XS. I’ve been told to run all different octanes and was wondering if you guys knew what was best..
thank you!
Wrong boards Sir, your motor is not a 3.0 liter.
My apologies- maybe a moderator can move..
You'll find the answer in the FAQ at the top of either the 3L or 2.5L forums, short answer is 87 octane and no more than 10% ethanol.
Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations
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Phil
'09 Hewescraft ProV
'09 150 Optimax
Thank you silverfox!
Welcome! Post any future questions in the 2.5L forum and be sure to include your engine serial number (required anytime you start a topic). Don will move this when he gets a chance.
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Phil
'09 Hewescraft ProV
'09 150 Optimax
My manual says I can use higher octane gas so that's I started using last season and my motor was running way better. This season I'll do the same.Originally Posted by cav
Your manual does not recommend using higher- though it may say it is "acceptable".
Carbon Buildup is one of the biggest problems we see- if you consider the condition of your rails and direct injectors (not to mention pistons, tuner, idle relief system, etc)- those items alone are definitely reason enough to stick with the specified octane.
This is something I work with every day... but the choice is obviously yours.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Well it runs like crap with 87 and I have buddies that have 600 plus hours on thier optis with nothing but 92 so... you are the expert but rough shitty idle or smooth power delivery and better gas mileage.... if it wasn't recommended then manual should say 87 only, no?Your manual does not recommend using higher- though it may say it is "acceptable".
Carbon Buildup is one of the biggest problems we see- if you consider the condition of your rails and direct injectors (not to mention pistons, tuner, idle relief system, etc)- those items alone are definitely reason enough to stick with the specified octane.
This is something I work with every day... but the choice is obviously yours.
"USA and Canada ‐ having a posted pump octane rating of 87 (R+M)/2 minimum. Premium gasoline (92 [R+M]/2 octane) is alsoacceptable. Do not use leaded gasoline."
My understanding of this quote from my manual suggests that 92 can be used so I do. In my opinion I'm not doing anything wrong. Not saying your incorrect just going by what the manual says.
Last edited by jtracc; 03-14-2019 at 10:39 PM.
A lot of this falls on the quality of fuel you are getting at the time you are pumping.
Things like never fueling after the gas station was just refilled by a transport (as this will stir up everything in the holding tank including water) Gas stations that tend to be secluded and not busy = old stale fuel and much higher chances of poor gas quality. The list goes on.
ive seen smaller 2 stroke engines bite the dust due to bad gas... heck ive personally melted 3 pistons on my old triple sled due to it a good few years back.
On that note though... are you adding fuel additives on your fill ups? The motor SHOULD be able to run on both fuels no problem.
If theres one thing ive learned.... if the manual says the motor can run on 87.. it means it was built for it and running higher octane will yield no actual benefit. Running too high of an octane rating can hinder performance as well.
I know you said it wasnt running worth a damn on 87... but technically it should..
Last edited by ride.race.live; 03-15-2019 at 06:52 AM.
2004 Ranger Reata 180vs 8" rapid jack magnum CCM reeds 21P tempest plus- 2005 150 optimax 1B044209
From the FAQ at top of forum - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations
Fuel Selection:
Make your fuel selections based on the following criteria, IN THE FOLLOWING ORDER:
-High Traffic, Top-Tier (Name Brand) Fuel
-Appropriate Octane Rating (see above info)
-Lowest possible ethanol content (NEVER to exceed 10%).
-While it may be preferable to utilize a fuel that contains lower (or no) ethanol, use of fuels that are SUBSTANTIALLY higher octane can result in decreased performance, decreased fuel economy, and potential for carbon buildup. Higher octane fuels burn SLOWER and COOLER.
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
i get it not my first optimax or boat. I live just north of the most populated city in the country so fresh gas is not an issue. I use fuel additive every fill up and I only pump in gas I will use up that fishing trip. I was using 87 from shell, it was giving me rough idle and hesitation often. (I had just completed 100 hr service) I tried 92 for the heck of it, manual says it's acceptable and buddies only run 92 in their optis so I tried it and after a few outings the motor purred like a cat. Personally the motor runs better on 92 and my dealer says run 92. The biggest issues they see with the opti is lower grade gas messing them up so... not saying the pros here are not wrong but the manual says I can use 92. If it didn't recommend it I'm sure Mercury would tell the owner not to use it.
All in the definitions of "Required" and "Acceptable". Glad you found what works for ya.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
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