Marvel Mystery Oil vs Sea Foam Motor Treatment

Cars are a big-ticket item and, just like anything else we spend our hard-earned money on, we want to keep our automobiles running smoothly as we pack on the miles. One was to ensure the life of your engine is with a fuel additive. In short, when you add products like Marvel Mystery Oil or Sea Foam, the oil is better able to function, which prolongs the life of your care. 

Marvel Mystery Oil and Sea Foam are two of the top products on the market and, if you don’t know much about cars, then you might wonder what they offer and how they differ. In this article, we’ll go over each product step by step and will do so in a way that you don’t need to be a mechanic to understand. 

Marvel Mystery Oil

Marvel Mystery Oil 1 Gallon
  • Helps clean engines.
  • Lubrication to control sludge.
  • Cuts down on wear and tear on car.
  • Helps with cold weather starts.
  • Can be added in with oil changes and in your fuel tank.
  • Increased gas mileage.

Sea Foam Motor

Sea Foam SF-16 Motor Treatment - 16 oz.
  • Cleans engine.
  • Lubricates to get rid of the gunk.
  • Cleans the fuel injector, the intake valve, and chamber pots.
  • Lubricates the upper cylinders.
  • Destroys residue and breaks down deposits with liquefaction.
  • Stabilizes both gas and diesel fuels for up to two years.

Marvel Mystery Oil

Marvel Mystery Oil company logo on the beach

This fuel additive was created to do much more than just burn out of the tailpipe with your gasoline. It was designed to enhance your engine by cleaning it up while adding a layer of lubricant. It is petroleum-based with other chemical additives. Mostly, this product is popular because it offers the same degree of engine protection as higher-priced comparative products. 

The History

Marvel Mystery Oil has been around for some time. Burt Pierce founded the brand in 1923 and was first successful in inventing the Marvel Mystery Oil Carburetor, which was included in 80% of the vehicles created on the assembly line after World War I. When the second World War came around carburetors, particularly the ones on jet engines, were clogging.

They discovered that the heavy lead content amongst other pollutants found in the gas they were using. Pierce focused on creating a product that could clean out the clogs. This was Marvel Mystery Oil. It was thus used in all the jet engines during WWII. 

The Benefits

Surprisingly enough, not only did Pierce’s invention help unclog the jet engines it also creates a top ring seal, produces higher compression, and prevents blow-by on power strokes, which means your engine will get more power. The wear and tear on your engine will be cut down dramatically and it controls sludge. 

You’ll find that your vehicle has increased gas mileage and it can help your engine deal with cold weather starts. It can be used in diesel, gasoline, marine, agricultural, and recreational engines. In other words, there aren’t any vehicles in your life that can’t benefit from Marvel Mystery Oil’s Mystery Oil. From the car to the snow-blower, you can add this to it. 

How To Use It

There are several ways to use this product, and it all depends on what kind of vehicle you have. For the sake of simplicity, the following instructions are for an automobile because that’s the most common vehicle with an engine used. 

Lubrication for Sludge Control

To do this, the next time you change the oil in your car, replace 20% of the oil you use with Marvel Mystery Oil and keep it up for every oil change. 

Increase Gas Mileage

All you need to do is add four ounces of this product to your tank with every ten gallons of gas. The average car has a fifteen-gallon tank so you would add six ounces every time you filled-up, but you should check the gallons in your tank before adding to get the ratio correct. 

Cleaning For Engines & Fuel Systems

To do this you would follow the directions for Lubrication and Gas Mileage. So, if you were planning on doing those then you’ll have this part covered. 

Cold Weather Starts

car on the road during winter

If you live in an area with cold months then you know what a cold-weather start means. How many of us have turned that key only to find the engine is dead. This happens because the oil thickens in the cold weather. The remedy put 20% of the crankcase capacity with Marvel Mystery Oil. 

Potential Problems

While the reviews on Marvel Mystery Oil are predominantly positive, there are some issues that have been noted so we would like to make you aware of them. 

Packaging Issues

It seems that there have been some issues with the bottle that the Mystery Oil comes in. There have been strange reports of opening a bottle filled with only water and another where they had two different gallons where the bottle broke and the product was lost as a result.

Also, another user had an issue with the child-proof cap saying that it does not work in keeping children out. Other reports have said the gallon size bottle pours terribly and always leaves a mess. 

Mixing With Gasoline

One user admits that the product does exactly what the company claims, which is great. Yet, it eventually began to clog his fuel lines. The remedy to that was to flush the fuel system more often. 

What The People Say

Now that we covered the negative points that consumers have pointed out, there is no denying that an overwhelming amount of users find this product amazing. Not only does it keep your engine clean from toxins, it helps the user get more miles out of their fuel than they would if they didn’t add Marvel Mystery Oil to the tank.  

Sea Foam Motor Treatment

Sea Foam Motor Treatment logo

Our comparing product is also a fuel additive and has nearly as long a past. Take a look. 

The History

Not much longer after Marvel Mystery Oil was putting out their Mystery Oil, Sea Foam began its journey in the 1930s. The founder, Fred Fandrei, started his career as a petroleum salesman who was a fan of fishing. When he realized he was spending more time repairing his outboard motor from problems that stemmed from the fuel, he decided to do something about it. 

He set out to create a petroleum blend that would help the motor run more efficiently while preventing the fuel from going bad. When he was done he passed it around to his fishing friends and they all found it worked. So Fandrei put it into empty beer bottles and quart-sized jars and started selling it to local fishermen. The name Sea Foam is a derivative of that history. 

Since then it has grown to be one of the most purchased fuel additives in North America. 

The Benefits

Sea Foam is made from petroleum-based products that won’t impair your engine or fuel system. It was designed to lubricate your engine and get rid of the gunk that can get stuck in it, just like Marvel Mystery Oil. 

After adding Sea Foam your fuel injector will be cleaned out and remain that way as well as the intake valve and chamber deposits. It also lubricates the upper cylinders and will destroy residues and break down deposits, turning them into liquid in the crankcase. 

Also, Sea Foam works as a stabilizer of diesel and gas for up to two years. It works with all motors both synthetic and conventional.

How To Use It

Sea Foam SF-16 Motor Treatment

Just like our previous product, how you use Sea Foam to optimize your engine depends on what results you are looking for. We broke them down for you below. 

Regular Fuel Maintenance

All you need to do is add one ounce of Sea Foam for every gallon of gas in your tank. 

To Clean

This requires a little more power so Sea Foam suggests you add two or more ounces per gallon to your tank. They also say that the more you use the better it cleans. For the best results add it when you have driven your tank down as low as it can get it. 

For Injector Cleaning Machines

If you plan using an injector cleaning machine then the ratio when you want to achieve is 50/50 of gas and Sea Foam.

Diesel Injector Cleaning Machines

Use 100% Sea Foam as well as when you are priming diesel fuel filters. 

Creating a 2-Stroke Pre-Mix

Add two ounces per gallon. 

To Stabilize Fuel For Storage

All you need is one ounce per gallon. It can stabilize fuel for up to two years. 

For Cars and Trucks driven daily

Add Sea Foam to the fuel tank every 3,000 miles.

For Small Engines

Add whenever you put more fuel in the tank.

For Engine Equipment Used Often

Add to a fresh tank of gas every three months or before. 

All Other Engine Types NOT USED REGULARLY

Add Sea Foam to every tank of fuel. 

Potential Problems

Other than reports of a few dented cans in shipping there isn’t much to report when it comes to problems with this product. Those who have used it seem happy with the results. There were a few who didn’t see a difference so this is one of those situations where you are going to have to get a can and find out for yourself. 

What The People Say

Sea Foam SF-16 Motor Treatment

When it comes to the positive things users have to say about Sea Foam they say it cleans the engine wonderfully and call it an excellent product. One heading called it “A tuneup in a can.” Needless to say, the majority of people who have used Sea Foam love it because the product lives up to its claim and reputation. 

The Real Difference

Now that we’ve covered both products extensively we know where they are similar. Both Marvel Mystery Oil and Sea Foam clean out engines, which prolongs its life. Also, but clear out sludge with lubrication. Here is how they differ…

Marvel Mystery Oil

  • Can be added to the fuel tank or when you change the oil.
  • Is an aid with cold weather starts.

Sea Foam Motor Treatment

  • Is only added to the fuel tank.
  • Is not an aid with cold weather starts.

Why Fuel Additives Are Important?

If you are a mechanic you already know the answer to the question but for those readers who may not be savvy with all things automotive, there is one main reason why either of these two products would be a good addition to your car care regime. 

Mostly because particles and debris gather in your tank, build up over time, and clog the fuel filter. Then your automobile may not start or begin to stall when you are in traffic. One of the worst results of a clogged fuel filter is an overheated engine, which could lead to some serious damage. 

For this reason alone it would be in anyone’s best interest to add this easy step into their automotive schedule. 


Use Marvel Mystery Oil if:

  • You are wanting to add a little extra to your oil change as well as your fuel tank.
  • You live in a place that gets cold.

Use Sea Motor Treatment if:

  • Cold weather isn’t an issue for you.
  • Fuel engine additives are all you are interested in.

To summarize our piece, both of these products have a long history of serving the automotive community and are giants in the industry. They do exactly what they claim, clean your engine of the sludge and gunk so that it works more efficiently, saving the life of your vehicle. Even though there are obvious differences, you can hardly go wrong with either product. 

If you have any questions please leave them in the comments section below.