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What Octane Gas For Mercury 2 Stroke Outboard – Our Recommendations

Gasoline For Mercury 2 Stroke Outboard

Gas stations offer the types of gasoline that are used mostly. As we know Mercury 2 stroke outboard is not being widely used nowadays. Despite this fact, Mercury recommends some fuels to run their 2 stroke outboards.

Some boat owners are in dilemma with the use of those and some are not sure which one is the best. This article is for them.

Are you looking out for what is the What Octane Gas For Mercury 2 Stroke Outboard?

We recommend 98 unleaded (SP98)  for our boat’s fuel tank (Mercury 2 Stroke Outboard). If you can still get unleaded 95, use SP95 with a fuel stabilizer.

Plus, avoid using E10 gas. If we use E10 gas, we must utilize a Mercury outboard motor stabilizer.

This article will tell us what kind of gasoline is best for a Mercury 2-stroke outboard. Scroll down to get the right information.

Gasoline For Mercury 2 Stroke Outboard

Gasoline For Mercury

Now we will acknowledge which octane gas is the best suited for our Mercury 2 stroke outboard. Additionally, we will know more about our dilemmas and their solutions for E10 gasoline.

So, it is important to know All About Outboard Gasoline. Let’s discuss and find out about all these.


The ratio of octane to heptane in unleaded gas 95 (SP95) is 95 to 5, with octane making up the majority of the fuel.

Despite the fact that it contains a significant percentage of ethanol, Mercury suggests this gasoline for most of their two-stroke outboard motors.

In point of fact, SP95 gasoline has a five percent ethanol content which is consequently 50 percent below E10 gasoline.

Using the SP95 instead of the SP95-E10 in our marine engine is a better choice.

It is possible to use an additive with this gasoline, although the dangers are far smaller than it is with E10 fuel.

When it comes to long-term upkeep for our Mercury outboard engine, we recommend using the SP95 plus stabilizer combination.

Due to its lower cost, SP95 has been the most popular gasoline among Mercury 2-stroke outboard engine owners.

Sadly, the SP95-E10 has steadily taken its position at petrol stations throughout the United States.



Octane accounts for 98 percent of SP98, while heptane contributes only 2 percent to the overall composition of the fuel.

Mercury recommends this fuel for use in all of these two-stroke boat engines, even though it does not specifically recommend SP95.

Well, marine mechanics have no choice but to go with this option. 98 unleaded gasoline is required for use in Mercury 2-stroke engines.

At the gas station, the price of SP98 is higher than the price of SP95. Because of this, they decided to go with the SP95.

Due to the fact that the SP95 is no longer available, the only choice available is the SP98.

Reasons to Choose SP98

Reasons to Choose SP98

We have some very good news regarding your financial situation. The SP98 is the best choice for you if you want to get the most out of your Mercury two-stroke outboard and maximize its potential performance.

To put it another way, if we want to keep the same speed, the engine in our boat will have to work harder than it normally would.

Because of this, it will have a lower impact on the environment. In terms of its consumption of gasoline, and the cost differential between gasoline and electricity will be eliminated.

Dilemma and Solution on E10 Gasoline For Mercury 2 Stroke Outboard

We are not so sure about using E10 gasoline for our Mercury 2 Stroke outboard because it can damage the engine. As a result, we should not use E10 gasoline alone, we can use it with a stabilizer. Let’s discuss this.


E10 is automobile gasoline. So, Fast usage is ideal for this. As a Mercury 2-stroke boat engine may spend months without being used, unlike a vehicle. That’s the issue.

Even if the Mercury instructions don’t warn against using E10 fuel, don’t. But in reality,  E10 gasoline will harm the outboard motor over time.

Well, the problems arise when E10 fuel dissociates from gasoline after sitting in a boat’s tank for weeks or months. Once liberated, ethanol will destroy our Mercury 2-stroke outboard. By detaching from the fuel, the alcohol will form pollutants.

This ethanol/gasoline separation has long-term effects. It may cause corrosion of parts and damage to the fuel pump, carburetor, injectors, etc. Plus, insufficient engine grease may be the cause of serious impacts during use.

However, check for how to remove gas from boat fuel tank. So, what can we do to avoid these problematic situations? Let’s find out the solutions.


E10 gasoline for mercury 2 Stroke Outboard

Using a stabilizer is the key solution if we use E10 gasoline to avoid hazardous situations.

Ethanol in E10 (and even SP95) won’t separate from the gasoline if you use a stabilizing solution.

Additionally, it prevents ethanol from reacting with atmospheric moisture.

There are additional benefits to using these stabilizers as well.

Your engine will start faster, and you’ll save money on gasoline.

Also, the E10 fuel in the tank will remain the same even if we don’t use it for weeks or months at a time, thanks to the use of fuel stabilizers.

In order to use a stabilizer, the gasoline filler is the only place where you need to add the stabilizer.

Rest your Mercury 2-stroke after that. This will aid in dispersing the fuel/additive combination throughout the system more evenly.

Note that stabilizers are only effective for a year.

Important Message

direct-injection 2-stroke engines

Outboards with direct-injection 2-stroke engines are no longer made by Yamaha or Mercury (although some are still made by Tohatsu), but the current generation of 4-strokes weighs the same as 2-strokes and has the latest digital advancements.

Mercury Marine’s outboard motors should be available in sufficient numbers once again, hopefully.

It’s no surprise that the company’s new line of lightweight four-stroke outboards, introduced last year, continues to be in strong demand.

Fortunately, four-stroke outboard motors are a viable alternative.

Mercury FourStroke 75, 90, and 115 are all available. Electronic Fuel Injection (EFI) systems are standard in all of these.

Check for Mercury 90hp 4 stroke problems or Mercury 20hp 4 stroke problems.

Besides, Mercury 2-stroke outboard owners have tested SP95-E10 fuel. Many have reported engine difficulties without Mercury’s explanation.

They all agree that SP98 fuel eliminated these issues.

Recommendation of Ours

Well, it is important to consult your marine engine’s operating manual first. Make use of unleaded 98. (SP98) Even though the price per liter is higher than others, we strongly advise using it in the fuel tank of our marine engine.

In addition, if you are still able to reach unleaded 95 at gas stations, you could try using SP95 as a secondary option along with a fuel stabilizer.

Anyway, avoid using E10 gasoline. In the event that we are unable to find any other options, we will be required to use it in combination with a stabilizer device for our Mercury outboard motor.


Octane Gas For Mercury faqs

Is it true that higher octane gasoline is beneficial for two-stroke engines?

If you have a four-stroke engine, 82 octanes would suffice, but if you have a two-stroke, you should seek the ethanol-free 92 and 93 octanes since the lower octanes are likely to explode.

Which are the high-powered outboards for your boat from mercury?

Mercury Verado 350, 400, and 400R outboard motors are our best options if we need a lot of power for our boat. These are some of the most powerful goods now on the market.

Which are the mid range 4 stroke outboards from mercury?

Some of the finest mid-range outboards that meet the new emission criteria are the Mercury V6 175hp, 200hp, and 225hp four-strokes.

direct-injection 2-stroke engines

Yes, you can use 93 octane gasoline in a 2-stroke outboard engine, but it is important to check the owner’s manual and manufacturer’s recommendations before doing so.

Some 2-stroke outboard engines are designed to run on lower octane gasoline, such as 87 octane, while others may require a higher octane rating, such as 93 or even higher.

Using the wrong octane gasoline can lead to engine performance issues, such as detonation (knocking), which can cause damage to the engine.

Additionally, using higher octane gasoline than what is recommended by the manufacturer may not result in improved performance and can lead to increased fuel costs.

It is important to always follow the manufacturer’s recommendations and use the correct octane gasoline for your 2-stroke outboard engine to ensure optimal performance and longevity.


Hopefully, this article helped you to come out from your dilemmas about what is the Best Octane Gas For Mercury 2 Stroke Outboard. Well, we recommend you to use SP98 and use a stabilizer with SP95 or E10.

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