Gumout question and answers.

Find below a comprehensive Q & A about all things Gumout

It is my understanding that the products listed as “Fuel System Cleaners” contain the ingredient PEA, but do the lower tier cleaners such as the “Fuel Injector Cleaners” and “Fuel Additives” also contain some PEA?

Also did the formulation become less potent with the “All in one” cleaner sometime between 2010-2012. I saw an older stock bottle and it looked much darker and smelled more potent.

Gumout All in One Comparison

Is there any reason to choose the lower tier products such as “regane or regane high mileage” over the “all in one” other than cost?



Fuel additives without PEA often contain a different ingredient called PIBA that clean carburetors and indirect port injectors. At high concentrations it can clean intake valves, but it does not clean combustion chambers. You need PEA to clean all three areas, fuel injectors, intake valves and combustion chambers.

All-in-One color variations were due to variation in some raw materials used in certain batches. The color change did not affect product performance, but we adjusted our production specifications to use only materials of the same consistent color so that the product color does not change. However, there still may be some older product on the shelf that is darker than others – feel confident in using the product regardless of the color difference because the potency is the same.

Gumout All-in-One can be used in any gasoline engine at the recommended treat rate, or even somewhat more concentrated. Regane and Regane High Mileage are designed to treat smaller fuel tank sizes – 21 gallons vs. 35 for All in One. However, High Mileage Regane has a friction modifier to help restore lost MPG and reduce upper cylinder wear. All in one has a larger dose of this friction modifier as well as more PEA. All three products can be used at up to double the recommended treat rate for even stronger cleaning.

I am a Techron user, how does Gum Out All in One compare? Does it contain PEA in equal or higher concentration in comparison to Techron?



Chevron doesn’t share their formulation information but independent testing that we conducted does confirm presence of PEA in their fuel system cleaners (FSCs). The PEA levels in our formulations are proprietary information as well, but a good way to compare is to look at how many gallons each product treats. All in One 10 oz bottle treats 35 gallons which is supported by industry recognized ASTM testing; Techron FSC 20 oz treats 20 gallons, their 16 oz treats 16 gallons.

Chevron doesn’t publically state how they determine their treat rates, but one would assume they have conducted legitimate testing.
In addition All-in-One has a friction modifier to reduce internal engine friction for better fuel economy. This is an advantage that Techron does not have.

Direct injection is reality. We have heard that some cleaning agents can “survive” the combustion process and clean through PCV or other means. This doesn’t necessarily make sense given HC regulations and the effect it would have on catalytic converters, however given the parallel reality of deposits in DI engines, cleanliness and additives to support engine cleanliness are essential. Can you describe the chemistry, mechanism, and tests/validation used to develop DI-suitable additives? Which of your products is most suited for maintaining valve, intake and injector cleanliness in direct injection gasoline engines, and why? (JHZR2)


We recommend PEA to clean direct fuel injectors. In a GDI (gasoline direct injection) engine the injector tip is in the high-pressure high-temperature environment of the combustion chamber. Carburetor and indirect port injector detergents are generally not made to survive the combustion process adequately to clean in this environment. However, PEA will. Since the tip of the injector is in the same environment as the rest of the combustion chamber the deposit characteristics are similar. They tend to be harder and more carbonaceous than the softer (and easier to clean) varnish and deposits found in cooler areas of the engine.

These deposits reduce fuel economy, reduce power, cause rough idling, cause hesitation and/or surging and cause hard starts. They interfere with air and fuel flow within the engine. Combustion chamber deposits cause knock and ping or even carbon rap that may cause severe engine damage. Modern computers may compensate for these deposits to some extent, but the trade-off is a lack of power and performance.

PEA is a polymeric molecule that contains portions that are more polar (the heads) that attach to the deposit particles along with a fuel soluble hydrocarbon tail. The molecule can then pull the deposit particle from the surface into the bulk fuel droplet where it is further combusted and/or blown out with the exhaust.

PEA is good at cleaning intake valve deposits (IVD) in port fuel injected engines because the treated fuel is sprayed directly onto the intake valve. However, direct injectors spray directly into the combustion chamber missing the valves. In some engines there is enough misting onto the valves when they are open to provide some cleaning, but in many engines the spray never reaches the IVD. In general we recommend an induction cleaning to take care of these deposits. Induction cleaning can also remove deposits formed in the intake manifold area that result from the crankcase ventilation system or other fugitive emissions.

Product performance is supported through a series of industry recognized ASTM laboratory bench and engine tests such as D6201 Engine Test, D665B Rust Prevention Test, D525 fuel stability test, just to name a few.

Engines are run and disassembled and the deposits are actually measured before and after clean-up using the PEA detergent. The appearance is viewed and rated and deposits are weighed in some areas of the engine or thickness is measure in other areas. Engine test stands, chassis dynamometers and vehicle fleets are all used to evaluate performance.

There is a substantial amount of testing and validation behind all Gumout Products. For more information about our fuel additive line of products visit

The ‘All in One’ 10 oz bottle claims to be good for “up to 35 gallon gas tanks”. If I used half a bottle in each of my cars (14 and 15 gallon gas tanks) would it be fully effective?

What is the PPM of PEA in this product?…in regular Regane?…. in High Mileage Regane?

Would it be more effective to add Regane before a long highway trip where the entire tank of gas is used or when the car will be used for several shorter trips where the PEA gets to ‘soak’ into the valves etc…?



Splitting a bottle of All-in-One as you suggest will be effective since you are close to the recommended treat rate. You can also use the entire bottle for increased efficacy.
The exact formula is a proprietary trade secret, please see our answer found above in the previous question. All three products do have PEA at a level that can clean the complete fuel system in one tank of gasoline.

Regane will show benefits whether it is added before a long trip (30+ miles at 60 MPH) or for shorter local trips. However, longer times are better because the vehicle runs at full operating temperature where the detergents are most effective.. On very short trips, the engine is not hot enough to support optimal combustion and allow the product to work its best. Overall we would favor a long highway trip at freeway speeds

Do any of your fuel additives contain anything to clean sulfur deposits from gas gauge sensors?



The damage to gas gauge sensors was the result of sulfur compounds causing silver corrosion. Silver corrosion was damaging fuel sending units and became a problem due to local refinery issues several years ago. The refinery issue was resolved and silver corrosion is not known to be an ongoing problem any longer. Unfortunately, once the corrosion has occurred, the only option is to replace the unit.

Gumout additives contain inhibitors that prevent corrosion on critical engine parts. However silver requires a separate inhibitor that is not part of our formulations since the refinery issue has been resolved and therefore not needed in our fuel additives.

I too would like to know which method of engine running would be more effective at cleaning everything. Steady highway rpm or city type driving. It’s been debated here more than once and I can see benefits to both methods but I’m guessing the city type driving would be more beneficial because of the varying cylinder pressures and volume of airflow changing rather than just a steady rpm, unless those rpm are high enough that it creates velocity.

And please not some bull form answer that both will clean effectively blah blah blah.



See previous answer to this question above.

Could you just list the concentrations of PEA in your products?



See detailed answer in previous question. We don’t share this info as it is proprietary just as Chevron doesn’t share their formulation details.

Does gumout use anything that would be considered better than PEA in their products for cleaning?



We continually investigate detergent chemistry to ensure we are using the most up to date and effective additives. Currently PEA is the safest and most effective technology available for cleaning the entire fuel system.

Please list the amount PEA contained in the entire bottle rather than percentage. The concentration alone is not the correct way to measure what gets eventually added to my tank. When I dump a bottle of your FSC or a competitor’s all I want to know what is the final PEA amount in my tank and it does not matter if you had double the concentration but half the bottle size.

Tell us how much gm/ml/oz of PEA each of your bottle has.



See previous answer to this question. We don’t share this info as it is proprietary just as Chevron doesn’t share their formulation details.

Your top 3 fuel system cleaners, (Regane, Regane high mileage, and All on one).

Do these 3 products contain the same percentage of PEA?

Why isn’t the All in one product available in Canada?



All three of these products contain the proper amount of PEA to clean a full tank of fuel as listed on the package label. The larger bottle of All-in-One does contain more PEA than Regane of High Mileage Regane; see previous answer for more details or visit for further information.

Retailers in Canada may have chosen not to stock All-in-One. It is available through or other internet retailers.