I have a 2014 Mercury 150 Pro XS. Everything I have read says to run 87 octane. A gas station has opened in my area that sells non-ethanol 89 octane. So which is better for my motor, 87 octane with 10% ethanol or 89 octane with no ethanol? Another concern is that it is a single pump off to the side. How much do they sell and how long have they had it.
That is a good question. I have ran both in my Etec 225 with no noticeable difference but the consensus has been to avoid ethanol. Given a choice, I would opt for the 89 E free.
Provided your boat is a 2014, you should have ethanol resistant fuel lines. As long as it is treated there really is not threat to your ProXS or its components. The motor is designed to run with 87 E10. I also know that 89 should burn just fine. Just make sure you run Quickleen in every tank. IMO, it is up to you and your wallet.
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I have the same motor, and based on some threads on this board and other articles I have read, the 89 octane has a different combustion profile, so carbon build up can be an issue more than with the 87 octane. 2 strokes don't like carbon for several reasons so I try to avoid anything that has potential to add to carbon buildup in the motor.
You have any links to the articles? I like reading this stuff. I've never ever had a carbon problem on a motor that didn't spend a lot of time idling. Pretty much have always run premium in most things and never had an issue, even low compression motors just because. I've been told by an engineer friend at Shell that the premium has a better additive package.Originally Posted by Macattac
I follow the recommendation in this FAQ topic - Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations
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Phil
'09 Hewescraft ProV
'09 150 Optimax
What you have been reading about octane must not have come from Mercury Marine. They do not say to use 87 octane. They say to use unleaded 87 octane minimum. As in, a higher octane is acceptable for use but a lower octane is not acceptable.
I read all of the time about problems arising from ethanol being added to gasoline. I don't recall ever having heard of a problem from the use of higher than minimum octane. Therefore, between the two choices you state (87 octane with 10% ethanol or 89 octane with 0% ethanol) I would choose the latter. The higher octane could very well offer you a bit of added protection against the onset of detonation.
Some will say that higher octane results in more carbon buildup. If so, there are treatments that can be done/additives that can be added to mitigate this issue. But then there are treatments/additives that can be used to mitigate ethanol related problems as well. You could always check your plugs for the presence of carbon buildup with 87 octane and then compare what you see to what is seen if you use 89 octane, to see for yourself if there is any noticeable difference.
Some will say that higher octane burns more slowly which might result in a loss of some WOT boat speed. Do you run your motor at WOT all of the time?
Octane - such a simple performance measure that results in lots of complicated discussions.
I have a 2014 150 ProXS as well. There are two new ethanol free gas stations that just opened up. They are close to my camp, but not close enough. Has anyone ever heard of an issue running a blend of 87 ethanol and 89 ethanol free fuel in their tank?
I don't know if I would run to the ethanol free stations on every gas run. I assume that running a mixed fuel blend would increase the octane and decrease the ethanol content. But I don't know if it is worth it.
'14 Triton 18XS 150 Optimax Pro XS Fortrex 80
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jethro1... you and I have had several previous discussions on this topic. Octane is NOT a PERFORMANCE MEASURE. While you do have some good understanding of the topic, you also seem to enjoy pushing folks into buying fuels that are more expensive, and offer NO benefit to their engine, whatsoever (in fact, may actually be worse for the engine).
All that being said: BEFORE POSTING IN THE FORUMS: Please read the ANNOUNCEMENTS at the top of the forum. Be sure to provide the REQUIRED info, and follow the relatively simply worded guidelines.
If you post here- you've AGREED to follow them.
Also a great idea to check out the FAQ Section, which contains a LOT of useful info, especially as pertains to the Original Poster's Question. See:
Oil, Battery, Spark Plugs, Fuel and Fuel Additive Recommendations
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).
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Performance was being used in the context of how gasoline with a higher or lower octane performs in the combustion chamber. Not as in how the motor performs with higher or lower octane. Motor should perform about the same. If not exactly the same.
I have no connection to anything related to the oil industry. I am not pushing sales of gasoline with higher octane. Don't have a dog in that hunt.
When folks ask about the use of lower octane gasoline with ethanol versus the use of higher octane gasoline with no ethanol, I offer some food for thought. It is not that the higher octane in the zero ethanol gasoline offers any benefit (it probably won't), it is the fact that the gasoline with the higher octane has no ethanol that might result in the benefit.
Engine makers caution all of the time to be aware of gasoline with ethanol. I don't recall them saying to be aware of gasoline with a higher octane rating.
Folks down in Florida have rec 90 available to them. It does not have ethanol in it. Lots of the folks down there are using the stuff just to not have to deal with ethanol issues. I don't read of them having problems with the gasoline just because it has a higher octane rating.
Would 87 with no ethanol be preferable to 90 with no ethanol? Absolutely. But they use what they use just to stay away from ethanol. It is the greater of the two evils, if gasoline with a higher octane rating is being seen as an evil. Which it certainly is to ones wallet.
Another thought has to do with motor usage and fuel consumed.
If a guy is running 100 gallons of gasoline a week through his motor(s) then by all means use gasoline with 10% ethanol with an 87 octane rating. The fuel being used so quickly will not lose any of its octane rating and the ethanol will have nil time to absorb moisture, possibly phase separate, or do damage.
Now if a guy uses 50 gallons of gasoline over a season then using non-ethanol 89/90/91 octane rating gasoline might be a benefit. Having zero ethanol means less likelihood of the fuel absorbing water and phase separation occurring. The gasoline will lose a bit of octane over time but since he started with more than is minimally needed he has a cushion to work with. Since his fuel usage is so low another 10 or so cents a gallon should not be a financial burden.
Just my 2 cents worth. Folks are free to do as they wish. Read all they can and find out what works best for them.
No problems using E10 if boat is used at least couple of time per month. I wouldn't hesitate to use "treated" higher octane none E if boat is seldom used or put away for starge. The thing that concerns me about the none E is if the station has a high turnover on that fuel. In FL and other coastal locations where this fuel is used on regular basis, none E even at higher octane level would be a better option.
I agree as well, I would much rather use 89 or 90 non-e than 87 e10
there isn't enough octane difference there to fuss over.
Just remember- these engines can't "compensate" for changes in fuel. And engines (such as the OP'ers engine) were built for, and calibrated specifically for E-10 fuel. That's quite different from the Carb/Efi models built in the 90's and earlier 00's.
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
Thanks, Don. I will continue to run 87 E-10 with Quickare and Quicklean.
Perfect choice.
According to the Manual For a 2014 Mercury Pro XS 250 the Min is 87 and the Max is 92 Octane. Page 52 under Fuel recommendation. Not sure if there is a difference with the different horsepower though.
Take a look again please.
One manual that I have indicates 87 minimum in the US/Canada and 92 minimum outside of the US/Canada. Nothing is said about any maximum.
Another manual says 87 minimum in the US/Canada and that 92 in the US/Canada is acceptable. It does not say that 92 is the maximum.
I wonder if there is an oversight by 93/94 not being mentioned. I shall see what Mercury Marine has to say on Monday.
Jethro... I think we've bothered Mercury Marine enough on this topic at this point. Read the manual, use what's recommended.
And let's let the topic rest at this point.
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 this is the range from the manual. 87 low end 92 at the high end is ACCEPTABLE according to Mercury.
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