What Grade of Gas To Use

[Thermobrett]

Here is a question I am sure a few people have asked or are thinking about.
On my 2022 SX195, I only use 91 octane or higher (if I can find it) as that is what the owners manual and stickers on the boat call out. I know several people have switched to non-ethanol for boats (outboards, I/Os and Inboards). In the owners manual it specifically states to use 91 or higher. Has anyone tried the non-ethanol in a jet boat and had any success or issues? Im under the impression the non-ethanol is better for the tank and hoses, but have never used it.

Years back I had a 1994 Sea-Doo GTS and could only run premium fuel in that as it had such a high output engine, anything less would cause it to bog down and/or stall out.

 

[Bluewater272]

Million threads on this, and you're about to get a bunch of pseudo-science. Bottom Line: your boat (and all fuel-handling components) was designed to run on fuel with up to 10% ethanol, just like your car. If you're using it regularly, that's fine. If it's laid up, add some stabilizer - no need to go out of your way to seek out ethanol-free fuel, just make sure your octane is right with the supercharged motor.

 

[FSH 210 Sport]

I only run non ethanol fuel unless I’m on a trip and can’t get it, then I’ll run 87 ethanol laced fuel. Once back home I’ll run the tank down very low and re fill with non ethanol. If you are going to run ethanol laced fuel you should be adding Star Tron at every fill up to prevent phase separation. I just had another example of phase separation come my way the other day, modern lawnmower with a solenoid operated run valve that was caked up with a thick gelatinous substance and would not function correctly, that was phase separated non treated ethanol at its finest.

The price difference in cost for me between non ethanol and ethanol is roughly $8 per 30 gallon fill up, in my opinion well worth it to avoid any potential problems.

Im a big believer in running what octane the manufacturer states, the manual calls for 86 octane in my boat and that is what I run, I use an online calculator to mix 85 & 91 non ethanol in the correct proportions to get 86, it’s easy. If your manual calls for 91 octane then that’s what you should run.

 

[Thermobrett]

Thanks. I assume the manufacturer did their research and that’s why it’s clearly specified. I have no issue with using premium fuel, just wasn’t sure if there was any pros/cons with it as I have never used it before. I have seen Star Tron advertised but never used it. I usually try adding a bottle of Sea Foam about every third fill up, figuring that wouldn’t hurt.

 

[FSH 210 Sport]

Thanks. I assume the manufacturer did their research and that’s why it’s clearly specified. I have no issue with using premium fuel, just wasn’t sure if there was any pros/cons with it as I have never used it before. I have seen Star Tron advertised but never used it. I usually try adding a bottle of Sea Foam about every third fill up, figuring that wouldn’t hurt.

I lost a fuel pressure regulator in my fuel injected dirt bike to ethanol laced premium because 1-I did not add any stabilizer, 2-I didn’t believe at that time ethanol laced fuel caused these problems.

That cost me a day of riding after I had driven 2.5 hours out to my riding area with my friend, and it took me a week to figure out what was wrong, I traced it to a fuel pressure issue and when I pulled the regulator it was covered with a white crusty substance and the regulator was seized. I did some research and from that point on I ran Star Tron religiously because I could not get non ethanol gas unless it was VP race gas which was ridiculously expensive. Now that live where non ethanol gas is readily available that’s all I run in my boat, dirt bikes, back up generator, Toy Hauler generator tank, and lawn and garden equipment. Properly treated non ethanol gasoline will last up to two years, and I think Star Tron makes the same claim on the label of their products. Come to think of it, my friend has a boat down at Bull Head, he takes very good care of all of his stuff including his boat. His boat started running poorly, took it to the shop and the fuel pump was trashed due to ethanol laced fuel. He now runs Star Tron marine religiously.

This is a fact, water bonds instantly with alcohol, that’s why the Indy car teams have buckets of water in the pits in the event of a fire. We run our boats on water… and as long as the water content in the ethanol is below its saturation point the water stays suspended, once the ethanol reaches saturation that is when the water/ethanol will drop out of suspension and will then start corroding fuel system parts.

Ethanol also has half of the energy / btu’s of gasoline, 44,000 btu’s vs. 95,000 btu’s. Side note, only a government could demand higher mpg numbers and at the same time mandate putting an additive in the fuel that has less than half of the energy.

I agree with @seanmclean that if you were running it all the time and it isn’t sitting a lot then the ethanol laced fuel will probably fine with an additive. Some folks around here use the ethanol laced fuel during the season, but start running non ethanol for the last few tanks before the winter lay up. There are two upsides to ethanol laced fuel, providing that it is dry. 1-Since water bonds instantly with alcohol it will remove any water that does get into the tank-this is what fuel system water removers are. 2-The ethanol acts as a detergent and will help keep the fuel system free of certain deposits, in fact one research paper I read on this subject talked about how an occasional tank of ethanol laced fuel was a good idea. I just run either Amsoil or Techron fuel system cleaner at every fourth or fifth fill up, I also run Amsoil upper cylinder lubricant with each fill up.

The way I look at it, since non ethanol is available to me, and with my past and current experiences with ethanol laced fuel I will pay the little bit extra to keep the water out of my fuel system.

 

[Thermobrett]

This is fantastic information, I will stop and pick up a bottle of Star Tron on my way home tonight. We usually use the boat every couple of weeks, and almost every weekend during the winter down here in Tampa, so the boat doesnt sit for long periods of time. Since I purchased it new, I want to keep everything as new as possible.

 

[TeenGee]

Highest octane non-ethanol fuel I can get.

 

[Alexegan88]

Only ethanol free, I actually fill my Jeep with it too, down here it’s usually sold with 89 octane. Slightly more fuel efficient and better for the engines. Will it make a “material” difference (extend the life), probably not, but if paying an additional $.75 a gallon it’s not a dealbreaker and you truly want the “best” option ethanol free is the way to go. Almost all marine engine manufacturers recommend it. Except of course if your engine is supercharged - as with all superchargers and turbo engines, you really need premium octane fuel - I have seen 93 octane that is also ethanol free, but it can be really hard to find.

Just watch some of those videos where they run two identical engines one with ethanol free gasoline and one with 10%. Ethanol free ALWAYS runs longer (more efficient) and when the engines are taken apart always looks a lot cleaner too. That was enough to convince me it’s worth it. Yes most auto and some marine engines are designed to take 10% ethanol - but that does not mean it’s good for the engines, it just means the engines are engineered to reduce the harmful effects of ethanol (not eliminate them).

 

[AZMark]

Where do you all buy ethanol free that isn’t on water?

Im not familiar with Star Tron but I use the wildly expensive Yamaha Engine Med RX every time I fill up, which I assumed also treated for ethanol.

Is Star Tron cheaper/better/treating a totally different problem?

 

[AZMark]

Highest octane non-ethanol fuel I can get.

91/93 is really not needed without the supercharger.

 

[Alexegan88]

Where do you all buy ethanol free that isn’t on water?

Im not familiar with Star Tron but I use the wildly expensive Yamaha Engine Med RX every time I fill up, which I assumed also treated for ethanol.

Is Star Tron cheaper/better/treating a totally different problem?

In Florida we have it all over, 1 out of 3 gas stations near the coast or lakes will carry it, especially any that are near boat ramps. Usually marked blue (like how Diesel is always marked green).

 

[FSH 210 Sport]

Where do you all buy ethanol free that isn’t on water?

Im not familiar with Star Tron but I use the wildly expensive Yamaha Engine Med RX every time I fill up, which I assumed also treated for ethanol.

Is Star Tron cheaper/better/treating a totally different problem?

Try this site….

https://www.pure-gas.org/

 

[scokill]

Where do you all buy ethanol free that isn’t on water?

Im not familiar with Star Tron but I use the wildly expensive Yamaha Engine Med RX every time I fill up, which I assumed also treated for ethanol.

Is Star Tron cheaper/better/treating a totally different problem?

Our walmart has it.

 

[AZMark]

Try this site….

https://www.pure-gas.org/

Thanks! There aren’t many here in the valley at all but it claims one that would actually be on my way to the lake has it. I’ll have to check it out, I know they dug up all their tanks a year or two ago so maybe they decided to add that.

 

[Julian]

This thread is mixing the issues of 1) Ethanol and 2) Octane. Two completely different topics.

1. I've used ethanol in my 3 Yamaha boats since 2003 - never had an ethanol problem ever. I do put fuel stabilizer/treatment in over the winter that is specific to ethanol.
2. Octane is for high compression engines and prevents pre detonation (aka engine knock). If your engine doesn't call for high octane fuel you don't need it, and are wasting money buying it for a non high compression engine. It would be like lighting money on fire - total waste! The added octane in high octane fuels does NOTHING for a standard compression engine (non supercharged or turbo charged engine - many turbo charged engines don't need it either). Use the octane level the manufacturer recommends. Now, if you use lower octane gas on a supercharged engine, the engine will adapt and effectively lower the pressure on your engine to prevent pre-detonation (you will lose some power - 20-30% ish).

 

[Thermobrett]

I ordered a bottle of Star Tron on Amazon that treat 48 gallons of fuel for under $7 and will deliver tomorrow. Something I will buy regularly and stock in the garage.

 

[Alexegan88]

This thread is mixing the issues of 1) Ethanol and 2) Octane. Two completely different topics.

1. I've used ethanol in my 3 Yamaha boats since 2003 - never had an ethanol problem ever. I do put fuel stabilizer/treatment in over the winter that is specific to ethanol.
2. Octane is for high compression engines and prevents pre detonation (aka engine knock). If your engine doesn't call for high octane fuel you don't need it, and are wasting money buying it for a non high compression engine. It would be like lighting money on fire - total waste! The added octane in high octane fuels does NOTHING for a standard compression engine (non supercharged or turbo charged engine - many turbo charged engines don't need it either). Use the octane level the manufacturer recommends. Now, if you use lower octane gas on a supercharged engine, the engine will adapt and effectively lower the pressure on your engine to prevent pre-detonation (you will lose some power - 20-30% ish).

Agreed, but I don’t think anyone was mixing them up, just pointing out that ethanol free is also “available” in different octanes, however, it’s rare to find multiple options. So if you want ethanol free, but the gas station only sells it in 89 and you have a supercharged engine - you’re probably better off going with regular 91. 89 is usually what I see which works fine for me with no superchargers. While I agree with you that it won’t make a difference for a lot of boats, it’s kinda like saying just because lots of people eat unhealthy and live well into their 90s that it won’t make a difference if you do. Ethanol free gasoline is 100% the superior choice, the ONLY downside is it’s more expensive which is somewhat offset by the greater fuel efficiency. Yamaha does indeed recommend using ethanol free gas on their websites, but it’s not “required” in the manual either as most engines are designed to handle the harmful effects of ethanol. If the spirit of the question was what is the “best” fuel option. Hands down that is 87 octane ethanol free for regular engines and 92 octane ethanol free for supercharged.

 

[King]

Agreed, but I don’t think anyone was mixing them up, just pointing out that ethanol free is also “available” in different octanes, however, it’s rare to find multiple options. So if you want ethanol free, but the gas station only sells it in 89 and you have a supercharged engine - you’re probably better off going with regular 91. 89 is usually what I see which works fine for me with no superchargers. While I agree with you that it won’t make a difference for a lot of boats, it’s kinda like saying just because lots of people eat unhealthy and live well into their 90s that it won’t make a difference if you do. Ethanol free gasoline is 100% the superior choice, the ONLY downside is it’s more expensive which is somewhat offset by the greater fuel efficiency. Yamaha does indeed recommend using ethanol free gas on their websites, but it’s not “required” in the manual either as most engines are designed to handle the harmful effects of ethanol. If the spirit of the question was what is the “best” fuel option. Hands down that is 87 octane ethanol free for regular engines and 92 octane ethanol free for supercharged.

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Buc-ee's ! ! ! !

Don't have them around me but, sure wish I did.

Worked on a project in South Carolina for a bit where a Buc-ee's was the closest 'lunch spot' and it rocked!

Sorry, yall can get back to talking gas now. I've had my moment.

 

[Smiley]

I use premium from Kroger or Costco on the way to the lake and store with non-ethanol and Sta-Bil when we put it up for the winter, just as a precaution. Manual says 91 or higher, so that’s what we buy.

 

[scokill]

This thread is mixing the issues of 1) Ethanol and 2) Octane. Two completely different topics.

1. I've used ethanol in my 3 Yamaha boats since 2003 - never had an ethanol problem ever. I do put fuel stabilizer/treatment in over the winter that is specific to ethanol.
2. Octane is for high compression engines and prevents pre detonation (aka engine knock). If your engine doesn't call for high octane fuel you don't need it, and are wasting money buying it for a non high compression engine. It would be like lighting money on fire - total waste! The added octane in high octane fuels does NOTHING for a standard compression engine (non supercharged or turbo charged engine - many turbo charged engines don't need it either). Use the octane level the manufacturer recommends. Now, if you use lower octane gas on a supercharged engine, the engine will adapt and effectively lower the pressure on your engine to prevent pre-detonation (you will lose some power - 20-30% ish).

Same here. I have put stabil in over various seasons but maybe 2 out of 15 seasons.