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Homebrew Sea Foam (SeaFoam) Motor Treatment Recipe


This page is not affiliated with Sea Foam or the Sea Foam Sales Company nor am I liable for how you use this information. Fixing an engine is certainly a lot more expensive than original Sea Foam, so be careful if you decide to do any experimentation on your engine.

Recommended Recipe

4 parts Diesel2 parts naphtha1 part IPA

Initial Experimentation

All references to ounces (oz) refer to fluid ounces volume, not weight or mass. I used Sea Foam Motor Treatment in the gas tank of our vehicles as a fuel system cleaner as part of my oil analysis testing and I thought they ran smoother afterward. When I read about this stuff, I discovered that it could be used in many more ways than just pouring it into your gas tank. When it is used in the gas tank at 1-2 oz/gal, it cleans and lubricates everything from the fuel pump and fuel injectors to the back of the intake valves in addition to stabilizing and drying fuel. Sea Foam Motor Treatment may be used as an engine flush by adding it to the crankcase oil at 1.5 oz/qt and running for 30 miles. This usage sounds very similar to the AMSOIL Engine Flush that I ran at a high idle for 20 minutes. I would probably run the Sea Foam as an engine flush at a high idle for 20-30 minutes and not run the engine under any sort of driving load. Sea Foam Motor Treatment may also be inducted into the intake manifold to clean the intake and valves. Sea Foam Trans Tune is a transmission flush, cleaner, and stabilizer product. The documentation says to add 1/2 pint to the transmission fluid, drive around for 30 minutes in all gears, and then perform the flush. It then says to add the other 1/2 pint to the new fluid for prevention.

I would like to keep some of this versatile and useful stuff around, but it is about $10/pint at my local Auto Zone, which works out to 62 cents/oz. Luckily, the MSDS is available online and the composition is relatively simple: pale oil, naphtha, and IPA. Sea Foam Motor Treatment and Sea Foam Trans Tune are both made of the same three components, but they use slightly different ratios. Luckily, I can purchase these types of ingredients myself at many local stores. Also, this interesting excerpt was on the Sea Foam FAQ: "Sea Foam is composed solely of three specially blended petroleum oils each having specific functions such as lubricating, cleaning or moisture control. There are no other chemicals (not even color dyes) included in the formulation. Being of the same basic petroleum chemistry as the motor oils and gasoline you already use in your engine, Sea Foam is completely compatible with all engine components, fuels, lubricants and other additives you may have in your engine. Sea Foam will not damage gaskets or seals, and will not interact in a negative way with motor oil or fuel, or the additives used in them."

I chose to make a 45-35-20 mass ratio oil-naphtha-IPA solution for initial testing, which falls in the MSDS ranges specified for the two products. This solution maximizes the non-oil components within the specified ranges, but it is impossible to tell if this is closer to the motor treatment product or transmission treatment product on the first try. This DIY homebrew solution has similar composition to the commercial stuff and costs much less. This preliminary testing recipe is approximately: 6.5 oz pale oil, 6 oz naphtha, and 3.5 oz 91% isopropyl alcohol.

The naphtha and IPA are pretty specific ingredients not open to much interpretation, but the generic term "pale oil" does not offer many clues. The term generally means oil refined until it has a straw yellow to clear color, which encompasses a wide range of petroleum products. However, the Sea Foam FAQ quoted above tells us that this component is probably for lubricating duty and is most likely thicker than naphtha and IPA. I mixed up batches using 20W-50 motor oil, pharmacy heavy grade mineral oil laxative, ATF, and Diesel fuel as the "pale oil" component, but the final viscosity and mixing abilities varied quite a bit. I used a small water bottle with a 3/32 hole drilled in the cap and the bottom cut off as a funnel to measure relative viscosity. I filled the bottle to a given line (about 6 oz), removed my finger from the hole, and started a stopwatch to measure the seconds until empty. I measured water at 58 seconds and gasoline at 54 seconds at 50 degrees F for comparison.

Here are the results of my initial 45-35-20 mass ratio testing with different oils:

Notice the clear separation line in the mineral oil and motor oil batches. This line would appear in a matter of minutes after shaking. The ATF did separate some, but it resulted in more of a wide gradient than a clear line and only appeared after a day or more. The Diesel batch showed little to no separation in the same time frame and looked closest to Sea Foam in color. The ATF and mineral oil batches were closest to the Sea Foam in terms of viscosity. The Diesel batch was less viscous than Sea Foam. So, the Diesel batch would not provide as much fuel system or upper cylinder lubrication as the other formulas with this mass ratio, but that may not be important for many uses. Using Diesel fuel as the "pale oil" component is also the cheapest option I tested. I tested a 50/50 mix of the Diesel and 20W-50, but the end solution's mixing ability was somewhere between 20W-50 and ATF.

Revised Experimentation

Next I tried a 4-2-1 volume ratio using Diesel, which brings the viscosity up to 59 seconds, is still within specified mass ratios, and is easier to mix. I used a single half-cup measuring cup to make the first test batch, but you can use any size container. The viscosity of this ratio is very close to the original Sea Foam and this batch has similar composition.

msds component purpose msds mass % homebrew component source component cost $/oz density g/ml volume mass mass ratio solution cost $/oz solution cost $/pint
pale oil lubrication 40-60 diesel fuel station 0.0215 0.85 4 3.40 0.60 0.0123 0.20
naphtha cleaning 25-35 naphtha Klean Strip, Home Depot 0.2100 0.75 2 1.50 0.26 0.0600 0.96
IPA drying 10-20 isopropyl alcohol 91% pharmacy 0.0900 0.81 1 0.81 0.14 0.0129 0.21

7 5.71 1.00 0.0851 1.36

This recipe costs about 9 cents/oz and $1.36/pint instead of 62 cents/oz and $10/pint for the original stuff. The price jumps slightly to about 10 cents/oz and $1.65/pint when you use high quality Iso-HEET instead of watered-down IPA from the pharmacy. This recipe is not Sea Foam exactly, but it is similar.

Potential Substitutions

Now, what about substitutions? If you still care about the drying component, you could replace Iso-HEET IPA with HEET, methanol, denatured alcohol, or grain alcohol as long as the percentage is high enough. The 91% pharmacy IPA has a little too much water in it to achieve good mixing with the other components, so I highly recommend Iso-HEET, which is much more pure. You could skip the drying agent if your application does not need it. I used Klean Strip VM&P Naphtha, which is an intermediate or medium naphtha. You could try a light naphtha like camp fuel (white gas) or you could try a heavy naphtha like charcoal lighter fluid. You could most likely substitute gasoline for naphtha considering that they have similar densities and are composed of many petroleum compounds with similar numbers of carbon atoms. Many gasoline components are derived from naphtha. You could substitute kerosene for Diesel in a pinch, but that would reduce the viscosity of the final mixture considerably. Many oxygenated gasolines have some (under 10%) alcohol in it already, so you could certainly reduce or eliminate additional drying agent if you use the right gasoline. The ultra-cheap-out two-part recipe would be:

2 parts Diesel - 1 part gasoline

This simpler two-component recipe matches original Sea Foam color better than any of the other recipes. The viscosity is very close to the original. You can smell the IPA in the original, but the two-component mix smells more like gasoline for obvious reasons.


So, how well does the recommended 4-2-1 homebrew DIY SeaFoam recipe work? That is difficult to prove without tearing down an engine or running it on a dyno. I have run the homebrew in the fuel system of all 4 of our vehicles (2 Land Rovers and 2 motorcycles) at least once. I felt it made our two SUVs run smoother and I felt it had no noticeable effect on the 2009 motorcycle with only 3000 miles on it. It had a dramatic effect on our carbureted 1994 Yamaha FZR600R with 33000 miles on it. It sat most of the winter and was running really rough in the spring. I ran a tank with homebrew through and it ran dramatically smoother afterward. I am going to continue to use it in the fuel system of our vehicles at every oil change like I had previously with Gumout and real SeaFoam. I have not inducted or sprayed it into the intake manifold because I feel the fuel injectors and carburetors of our vehicles do a good job of spraying at the back of the intake valves. I might think differently if we ever get a direct-injection engine. I have run some homebrew through the crankcase of one Land Rover as an engine flush when switching oils and noticed no ill effects. Finally, I used it most recently to stabilize the last full tank of gas in one of our motorcycles before parking it for the winter.