Should I use premium gas in my 2 stroke outboard?

So, you’ve bought premium gas for your 2-stroke outboard for your boat? Wondering if you’ve obtained the right kind of gas for your engine? You keep silently nodding your head, so we’ll take that as a YES to both questions.

Do most boat owners worry about the effect the gas they’re using will have on the engine? Well, it’s hard to say. Let’s say they do anyway. If you’re one of them, you’ll enjoy the article we’ve prepared for you today. You’ll enjoy this one, too.

Consult your owner’s manual. If it doesn’t say you’re required to use premium gas, then maybe you shouldn’t. Most 2-stroke outboards run pretty well on regular (octane level 87) gasoline. Now, premium gas does have its advantages. It can last longer in storage and some types of it don’t contain ethanol.

On the lookout for more than just this forty to sixty-word preview? Feel free to check out the article below.

Table of Contents

What’s a 2-stroke outboard anyway?

Now, it’s not like we have an engineering diploma. Let’s take a guess and say that’s not so hard to assume. Still, we’ll try to explain this in the simplest terms possible. So, what exactly is a 2-stroke outboard?

An outboard is a synonym for an engine. 2-stroke engines were by far the most popular among boat owners. Why’s that? Well, they are simple, lightweight, and easy to use. When you consider the power they produce, they’re ridiculously light.

Here’s the sad part: their dominance came to an end back in 2004.

What happened in 2004?

The famous EPA (Environmental Protection Agency) enacted stricter limits on pollutants. Three years later, the restrictions became even stricter. It was pretty evident that 2-stroke engines needed to be reinvented. They needed to become quieter and cleaner running, like their 4-stroke siblings. In return, the 4-stroke models were to become lighter.

Differences between 2-stroke and 4-stroke engines

Of course, there are differences between these two types of engines. The main one, probably, is the duration of the combustion cycle process. Let’s take a closer look:

  • in 2-stroke engines, the fuel (pre-mixed with oil) is consumed every two strokes of the piston. To put it differently: power is produced once every two strokes of the piston.
  • in 4-stroke engines, as one can assume, the fuel is used once every four strokes of the piston. Also, they don’t require you pre-mix the fuel with oil.

Aside from that, they have other differences. For example, 4-stroke models are more environmentally-friendly. On the other side, 2-stroke engines are smaller and much easier to fix. Also, 4-stroke engines are much quieter than their 2-stroke competitors.

Now that we’ve gone through some basic info on engines, let’s see if we can say a word or two about premium gas.

What is premium gas?

The best way to acquire some info concerning premium gas is to compare it to regular gas. That’s exactly what we’re gonna do now.

Premium gas vs. regular gas

Their main differences lay in octane levels:

  • Gasoline with an octane level of 87 is usually labeled as regular. Also, gasoline with an octane level of 89 is generally labeled as midgrade.
  • Gasoline with an octane level of 91 or greater (91 and 93 being the most common) is labeled as premium. Some gas stations label the 93 octane gasoline as ultra or super-premium.

Fuel with higher octane levels is more likely to withstand the so-called detonations. The higher the octane level, the lower the chances of a detonation happening at the wrong moment. A single detonation can’t harm your vehicle that much. Although, if it happens a lot – there’s a chance you’ll see a decline in the engine’s performance.

Wait, what? A detonation?

Although the term sounds very dangerous, let’s take a look if it’s something that should bother you. Detonation is a pinging sound you can sometimes hear while accelerating. It’s a combustion of the air and fuel combo. It, of course, happens in the chamber after regular combustion is started by the spark plug.

So, it is dangerous? If it happens at the wrong time, it can leave some consequences. Some folks would rather use premium gas because of its ability to handle this issue. As we’ve said, a higher octane level lessens the chances of bad-timing detonations.

Let’s not forget to mention premium gas is a bit more expensive than regular. A gallon of premium gas costs about 50 cents more than regular gas. Is it worth the money? Let’s check out the paragraph below.

Is premium gas better than regular?

Well, the answer to this question isn’t a clear YES or a NO. Some vehicles require you use premium gas, some don’t. If your vehicle doesn’t demand you sip premium gas in it – you shouldn’t!

Owner’s manuals for some vehicles only recommend you use premium gas. Those vehicles run smoothly on regular gas also, so the choice is yours. Some of them showed better performance results when they were running on premium gas. Still, it’s really up to you if you’ll pay 50 cents a gallon more!

Does premium gas vary from state to state?

Well, as a matter of fact – it does. Some states label gas with a level 90 octane rating as premium, some don’t. Always check out the sticker on the pump to see which one you’re getting.

A group of silver/mettalic 2-stroke engines.


Should I use premium gas in my 2 stroke outboard?

Alright, so we’ve come to the main section of this article. Should you use premium gas in your 2-stroke outboard? Let’s see those arguments.

Gasoline loses octane over time

Let’s say you’ve decided to store gasoline during 0ff-season (here’s how to do it safely). Another fishing season’s over, and you’re getting ready to lay low for a bit. Imagine it turns out you’ve got some excess gasoline. Would it be better if that gasoline was premium or regular?

Gasoline with higher octane level is generally better for storage. Regular gasoline (octane level 87) will start to degrade in about one to three months. If it’s properly stored, that is. On the other hand, premium gas (octane level 93) can survive for up to nine months in storage. Now, of course, don’t forget to store your gasoline in a proper manner. You’ll feel much safer and the storage period will be prolonged.

So, yeah, premium gas has more stamina, if we can say it like that. But, is this enough of an argument?

We almost forgot to mention. Let’s say the fuel stays inside your boat for a longer period of time. Since some types of premium gas are ethanol-free, they’re the better option.

Are 2-stroke engines designed to run on premium gas?

Most folks use regular (octane level 87) gas in their outboards. If you were to check out online forums concerned with this topic, you’ll notice something. That is: users like to point out how their boat engines function pretty well with regular gas. So, is that the answer we need?

Well, it depends. Two-stroke engines are designed to run on regular gas without any trouble. Most folks argue that premium gas just isn’t worth the money, while other praise it.

Why do they praise it?

As we’ve said, some praise because some types of premium gas don’t have any ethanol. Others just like putting better gas in their vehicles. The thing is: using premium gas in your 2-stroke engine cannot hurt. 

Check your owner’s manual

We’ll only repeat ourselves here. It might be best to consult your owner’s manual. It will most likely contain info on which type of octane level is recommended. If it doesn’t demand you use premium gasoline then maybe you shouldn’t.

A quick recap

Okay, so we’re getting near the end of the article. As always, we’d like to point out some key elements of it. Here’s what we’ve learned today:

  • Differences between 2-stroke and 4-stroke engines. The main one lays in the duration of the combustion process.
  • Prior to 2004, 2-stroke engines were the most popular outboards out there.
  • In 2004, EPA introduced stricter policies. Four-stroke engines became more popular. That’s because they’re more environmentally friendly.
  • Differences between regular and premium gas are most concerned with octane levels. 
  • Gasoline with an 87 octane rating is usually considered regular. Octane levels for premium gas go from 91 to 93.
  • Premium gas can better withstand the so-called detonations. 
  • If your owner’s manual doesn’t demand you use premium gas – maybe you shouldn’t. At least that’s what most folks say.
  • Premium gas is better for storage. In proper conditions, it can last for up to nine months.
  • Most 2-stroke engines are designed to run on regular gas without any trouble.

Final words (A conclusion)

So, that’s about it, folks. This was a longer answer to the question “Should you use premium gas in your 2-stroke outboard?”. Hopefully, you’ve found out some new info in this article. Also, we hope you’ve enjoyed reading it!