Gumout question and answers.

Find below a comprehensive Q & A about all things Gumout

1. Interested in GDI fuel system maintenance, from tank to high pressure pump to injectors and upper cylinder. Is there a product with DI in mind?


Our Complete Fuel System Cleaners (CFSCs), Regane, High Mileage Regane, All in One and Multi-system Tune-up all have Polyetheramine (PEA), which is the only known cleaning agent that can survive the harsh temperatures found in the combustion chamber. It can remove hard to remove carbon deposits that rob your engine of performance. So not only can it clean the piston tops, cylinder heads and cylinder walls, but it can also clean up deposits found on GDI injectors and keep them clean for up to 3,000 miles. The chemistry also cleans up deposits from fuel tank, pumps (including high pressure) and fuel lines.

2. I almost always use Gumout All in One but occasionally use the octane booster. Does the octane booster have PEA in it? The side of the bottle lists its dangers and lists Amines. I run both of your products in a 2012 Hyundai GDI with 0 ethanol fuel and pennzoil synthetics. Mileage is 118,112 and I still get 38mpg+


No, our Octane Booster doesn’t have PEA in it. In fact, it has only a small amount of injector detergent. Our Octane Booster’s main benefit is to boost octane rating and help stop knocking and pinging and restore lost performance

3. How does your product keep GDI (direct injection) intake systems clean when fuel doesn’t reach Intake Valves in a conventional PFI way?


Our Complete Fuel System Cleaners and Multi-System Tune-Up will clean direct injectors by using PEA simply by pouring the product into the gas tank. However, since the injector in a GDI system is no longer in the port, buildup can occur on intake valves and is a lot tougher to remove. To clean the valves and ports in a GDI system, we recommend using our Multi-System Tune-Up by introducing the product using the induction method. This requires the product to be slowly introduced to the intake system via a vacuum line. This provides a concentrated dose of product that will help remove valve and port deposits in GDI systems

4. How much PEA does your “All in ONE” product have? I understand you can’t give exact percentages. How about a small range then? “Like ALL IN ONE has between 50% and 60% PEA.”


Please understand that the percentages of PEA in our products are proprietary, but all of our Complete Fuel System Cleaners have the correct amount to clean up deposits in just one fill up. What differentiates them are the other conditioning additives in the formulations and the amount of gallons that can be treated.

5. Can Gumout provide more before and after photos/videos of their product in action? Words are great but pictures (especially videos) are even better.


Please visit and for relevant videos and pictures. However, keep in mind that Complete Fuel System Cleaners take time to remove deposits. They typically remove deposits by the time you have gone through a tank of gasoline. So, depending on your driving habits, this could be a week or even a month, so it’s virtually impossible for a video to show this cleaning action over this time frame. Before and after images and videos are the standard for showing the benefits of using the product. We continue to test our products and will provide more photos and results as we get them. You can visit and visit our Science pages for updates.

6. Can any product (including Gumout) “fix” old gasoline? At least one product claims it can. Or does “old” gas need to be tossed?


While we don’t know of any product that reliably restores degraded fuel, we do have chemistry that keeps fuel fresh in storage. We recommend about 1 ounce/gallon Gumout Multi-System Tune-Up to treat fuel for any seasonal or marine engine whenever it may need to be stored or when it may need the fuel system cleaned up. This works well in 2-cycle engines also but does not replace the oil mixed with the fuel.

7. Does Gumout all in One really cleans piston crown carbon deposits? How much percent for each treatment?


We have independent test results that consistently show All-in-One really does clean piston deposits. The percentage cleaned varies from vehicle to vehicle and even from piston to piston in the same engine. It depends on the engine, the fuel and the driving cycle, so we cannot give a percentage for a specific engine.

8. Are you aware of ChrisFix video on youtube about it?


You would need to be more specific about what “it” is you are referring to for us to comment.

9. How many octane points does your octane booster raise a tank of gasoline?


An octane point is a tenth of an octane number, so a ten-point increase raises the fuel octane about one octane number. When used as directed, Gumout Octane Booster typically raises fuel octane about ten points. The exact number depends on the octane response of the specific fuel used and the exact number of gallons treated. Also, using more product will increase octane but less than expected. If one bottle increases octane 10 points, two bottles will not increase 20 points

10. Do you have before and after images from a borescope?


Most of our data is quantified by weighing deposits or measuring their thickness. This is much more accurate. There are specific examples where borescope pictures show improvement, but to the untrained eye, the pictures are not convincing and may be misleading.

11. Do your amines survive combustion and if so, are they effective in cleaning the EGR valve?


Our products that have PEA can survive the combustion chamber environment. It will clean the EGR valve if the formulations with PEA are introduced through the induction method that involves applying the product via the correct vacuum line. See the answer to question 21 for more details.

12. What is the mechanism by which additives keep a direct injection system clean? If they combust fully, how do they support cleaning of valves and other locations where DI engines are known to foul? If they survive combustion, how do they not cause excess HC emissions numbers and failure by the EPA?


Please review the previous answers for your first two questions. The PEA formula we use cleans injectors and intake valves as it flows past them before going to the combustion chamber where it survives long enough to clean those deposits. It is burned but burns cleanly unlike many old style oil based additives. These produce more char, leading to deposits of partially burned material. PEA is designed to burn cleanly without leaving ash or carbon behind. Emission reduction is the result of the cleaner engine performing better. During the cleaning process, emissions may not be immediately reduced. Emission testing should be run after the deposits are removed, not during deposit removal. The valve deposits in direct injection gasoline engines may not be removed by a fuel system cleaner added to fuel. To clean those deposits, we recommend the induction method where product is introduced through the vacuum intake. Severe deposits may require disassembly and mechanical cleaning.

13. Some of your additives containing PEA can be used in the oil as well as the gas. What purpose does PEA serve in the oil?


Assuming it cleans sludge and varnish in the crankcase, PEA is not specifically designed for use in the crankcase but still retains its detergent properties. There are other additives in the Gumout Multi-System formula that loosen sludge and varnish, particularly if used just before an oil change. Longer term antioxidants stabilize the oil reducing the oxidation that results in sludge build-up.

14. I have a vehicle known for oil consumption due to coking at the piston rings.Some people have had success using various cleaners or solvents to perform a “piston soak” on the vehicle. Is Gum Out “Expert” Multi System tune up appropriate for use in a piston soak? Will it provide any ring cleansing if used in the crankcase?


Gumout Expert Multi-System Tune-Up will provide a solvent soak, although the concentration recommended is at level that will not to provide this benefit. That is because the high concentration needed for a solvent soak will dilute the oil beyond the safe limits of engine operation. That is why we do not recommend this approach.

15. Will Gumout Multi System cleaner help with regards to cleaning engine varnish if added to motor oil?


Yes, and an additional effect is to prevent future varnish build up because the formula contains antioxidants that help prevent oil degradation.

16. CRC says % of PEA in their product, and considering they are your competitor, I feel like you also should specify the same info.


CRC has a very large portfolio of products. You will need to be more specific in order for us to answer your question.

17. I have used gumout carb spray and throttle body cleaner for as long as i can remember and always had good results. Although I had a number of cans that had spray issues over the years. I used to also use the gumout in the gas but i have switched to Techron not for any special reason.


If there isn’t any special reason, we’d love to have you return to Gumout. Hopefully the information provided on this forum and our website will provide you with enough information to make an educated decision on which product is right for you. The key thing is that you are doing the right thing by wanting to maintain your vehicle.

18. Is there a concern over using gumout products with PEA during the middle of oil change interval?


There is no concern. All our PEA products may be used at anytime during, before or after an oil change. They have been tested and show no ill effects to the motor oil.

19. Can gumout improve winter startup and do you have pictures and or videos to show the improvements using gumout with PEA?


Gumout All-in-One and Multi-System Tune-Up all clean the complete fuel system to make the vehicle easier to start and run more smoothly whatever the weather, but this is particularly important in the winter. The motor oil is also a major factor in Winter startup. Use the manufacturer-recommended oil viscosity for the winter and avoid heavier weight oil or oil thickening additives to let the engine easily turn over at start-up.

20. Will gumout with PEA clean egr,pcv, and other emissions sufficiently over time or over just one application bi monthly?


Gumout with PEA provides one tank clean-up, so benefits will start after just one tank. Bi-monthly application, or every three thousand miles, will reduce deposit buildup before problems develop and keep the engine running at peak efficiency. EGR and PCV are not directly fed by the fuel system. They vent the crankcase through the intake manifold and past the ports and valves. To clean these items, an induction procedure is done either as a fuel system service done by a professional or through the DIY method mentioned in the answer to the question below; however, Regane or All-in-One will clean ports and intake valves in a port fuel injected vehicle.

21. I use CRC intake valve cleaner for GDI, can your all in one or multi purpose bottle that resembles the stp and seafoam be used to directly to clean the throttle body and manifold if applied through spray mister and squirt bottle?


Yes, our Multi-System Tune-Up can clean valves and port in GDI engines as long as it is introduced to a vacuum line that leads to the intake system – never use the vacuum line that comes from the brake booster. It’s important that the product is introduced at slow rate to avoid vapor lock that can cause damage to the vehicle. When used correctly, our Multi-System Tune Up will provide maximum cleaning power to help remove the performance robbing build up in GDI systems – by pouring half in the tank and half via induction, it provides a powerful 1-2 punch.

22. Do Gumout products provide lubrication to the fuel system?


Our Regane High Mileage Fuel System Cleaner, All in One Complete Fuel System Cleaner and Multi-System Tune-Up all have friction modifiers to provide lubrication to the fuel system. All-in-One has a high level of friction modifier, while Regane High Mileage has a lower amount. Gumout Multi-System Tune-Up has different chemistry, so we cannot compare performance directly, but it also demonstrates friction reduction compared to untreated gasoline.

23. Do you products work well in small engines?


Yes, the ratio of product used would be different but will provide the same benefits. Please read the directions on the products to know what amount of product is the optimal amount for your small engine.

24. Gumout Professional Pro 2 Step cleaner is being sold at Ollie’s Bargain Outlet. The intake portion needs an applicator which is unavailable. Can the intake bottle be used in the gas tank. Will it benefit the vehicle to use it this way. Does the gas tank portion have any PEA in it?


This product was not intended to be sold to the general public due to the skill level and equipment needed to properly and safely use the product. Another concern is when product is sold to bargain outlets, not through our sales channels such as in this case, because the product age may be beyond the shelf life that we recommend. Typically we do not recommend using any of our products if they are older than 4 years old. Please call our hotline and provide the coding on the packaging, and they can determine the age of the product. If the product is still within the approved date range, the liquid intake cleaner can be used in the gas tank and it does have PEA in the formulation.

25. Why should I use gumout over other brands such as lucas, seafoam, royal purple etc?


There are many products and brands that claim to do a lot and some of them can back up their claims and others can’t. We at Gumout are being as transparent as we can about the ingredients we use and the certified tests conducted to prove that our products work. We recommend you search for similar information on these other products from the company’s websites and official documents. If they don’t provide this information, ask for it. If they aren’t using ASTM industry recognized testing methods, be concerned. If they won’t provide you with this certified test results, then our recommendation is to go with the brands that are willing to give you the information you need to make the right maintenance choice.

26. How well does Gumout work with ethanol in gas?


All Gumout products have been extensively tested with E10, the 10% ethanol fuel required for most areas of US. Performance is effective in this fuel and E10 was used for much of our testing program to support performance claims. If ethanol is a concern, particularly with marine engines, we specifically recommend treating the fuel with Gumout Multi-System Tune-Up to prevent damaging effects of oxidation and corrosion and to keep the fuel fresh during storage.

27. I am confused by how your fuel treatments are marketed. Regane Complete, Regane High Mileage, and All-In-One Complete seem to serve the same purpose. I never really know which one to choose since the only thing discerning them are their names and sizes. Why not simplify it to one formula? Do I get more detergents by buying the All-In-One/Regane High Mileage over Regane Complete? Is it possible to use too much or too often?


All 3 have PEA as the cleaning agent, High Mileage Regane has an additional friction modifier to lubricate upper cylinders, which is especially helpful for older vehicles that may have more wear and tear than newer vehicles. All in One has more PEA and friction modifier and treats more gallons than the other 2 products, so it provides the most benefits of the three items. We provide consumers with multiple product choices based on what their engines need, how many gallons they want to treat and the value they place for each product. Regarding how much to use, we recommend using one entire bottle before you fill up. Each of these three products will last up to 3,000 miles.

28. How is Gumout better than similar competitive products?


See answer to question 25 and visit our website and

29. Could you compare and contrast the product lineup differences between Canada and the United States for us? Up here, we customarily see Gumout REGANE Complete Fuel System Cleaner and the High Mileage version, and I’m under the assumption that these are two of your top products.


You are correct. These are two of our top products. Both are complete fuel system cleaners that clean port fuel injectors, intake valves, combustion chambers and direct injectors. In addition, High Mileage Regane also lubricates the piston ring/cylinder wall area to reduce internal engine friction, providing better fuel economy.

30. What gains can a consumer who purchases only Top Tier certified fuel expect by using a fuel system cleaning/lubing product at a regular interval, versus only using Top Tier certified fuel? As a follow up, if a consumer uses non Top Tier fuel, would you say that regularly using a fuel system additive would leave the fuel system in the same state as a consumer who only used Top Tier fuel without using additional additives?


Top Tier Fuel is recommended because it does a superior job of preventing engine deposits overall. However, it does not completely eliminate all deposits. Recent studies have shown that, even with top tier additive chemistry, fuel from some sources continues to build deposits, so an additional fuel system treatment will show benefits. If non-Top Tier fuel is run in the vehicle, then complete fuel system cleaners are usually needed to clean up the engine. The best results come from regular use to keep deposits at a low level before they reduce performance. This is not exactly the same as using Top Tier fuel consistently. Overall, the combination of Top Tier Fuel with the occasional Fuel System Treatment is ideal.

31. I would appreciate any before and after pictures you may have of cylinder combustion chambers/top ends. Especially showing change after a single treatment or multiple treatments with Gumout products. Before and after pics of various top ends using Top Tier Fuel(with descriptions of mileage and drivng type, severe stop and go vs extended highway miles) vs Top Tier+Gumout would be impressive and if convincing….would be the BEST marketing strategy you could possibly provide


In our laboratories, we use numerical data to quantify our results and determine how much improvement results from using Gumout additives. To us, the numbers are more important and clearly indicate the level of performance. However, pictures are excellent at communicating results, so we are investigating the addition of additional pictures.

32. PEA concentrations per bottle?


While we cannot discuss specific formula details, we can let you know that when you buy a bottle of Gumout Regane, Gumout Regane High Mileage or Gumout All-in-One Complete Fuel System Cleaners most of what is in the bottle is the additive package we use to deliver performance. One of the critical components is PEA, but other molecules are also used to make the formula even better than PEA alone. Each contains some added solvent to assure proper delivery and dilution, but Regane has more than 70% additive, Regane High Mileage has over 75% and All-in-One has about 80% by volume in the bottle.

33. Is there a difference between the “high mileage” and the “Complete” products both with Regane?


Our High mileage version of Regane has a dose of friction modifier added to lubricate upper cylinders. Both products have the same level of PEA cleaning agent.

34. The optimum method for application says it treats 50-70 litres of fuel. That is pablum for the general public. I really want to know if I add a full bottle to eg: 20L of fuel am I going to get the results I am looking for in cleaning my fuel pump, injectors etc vs 40L or more.


Add a full bottle to a full tank of fuel in any passenger car. 50-70 liters is a recommended treat rate and the minimal dilution level used to test performance claims on the label. A smaller tank will have a higher concentration, so cleaning will be faster but may occur over a shorter period of time depending on tank capacity and fuel economy. You will get the results you want. However, use when filling the tank, since the product is not a fuel and the engine needs the petrol (gasoline) to burn properly when running the vehicle.

35. I was looking at the Gumout website and it seems like there are a lot of products that say they will clean the combustion chamber but I’m wondering which one of those products does the best job of this particular task? That’s my biggest concern when using a fuel system treatment personally.


Our Complete Fuel System Cleaners and Multi-System Tune-Up all clean the combustion chamber effectively; however, the difference between the products are the addition of other additives that help condition the engine. All will have a high cleaning level. As an additive to pour into the tank, Gumout All-in-One treats the most fuel (35 gallons) and provides the most PEA, so it will have the highest treatment level if used in a smaller tank. Multi-System Tune-Up offers the most choices where to use and is an excellent fuel stabilizer, so it is the best choice for a broad range of applications.

36. I have been happy with the Gumout All-In-One cleaner I had been using, and felt even better about it after reading the Q&A regarding the PEA content. I have been looking for one simple, short, easy answer. Which product is the best/most effective to use as an in the tank fuel system cleaner? All-In One or Multi-System Tune Up?


Our Multi-System Tune-Up product has a few more benefits than All-in-One such as: it can stabilize fuel and oil, it can be used in diesel engines and can also be used in the crankcase. If you don’t need these additional benefits, then All-in-One is still the right choice, but if your vehicle can benefit from these additional benefits, then head down to your favorite store and pick up a bottle of Multi-System Tune-up.

37. Are the Expert Series the same as the above mentioned products, only marketed for Autozone? Or do they differ?


The Fuel system treatment is new to the Gumout family. It is the same formula as our fuel injector cleaner, but we’ve added an upper cylinder lubricant to provide wear and tear protection between the piston and cylinder wall. Expert Series Regane and All-in-One offer the same cleaning and conditioning benefits of their non-Expert Series counterparts. Also, within the Expert Series line, are two kits: Horsepower and Performance restoration. These are unique to the Expert Series line and offer specialized products to help get you the most out of every mile.