510011 Multi-System Tune-Up, Fuel Stabilizer Injector Cleaner & Gas Treatment, 16 oz, Full Fuel System Cleaner - Improves Engine Performance, Cleans & Removes Deposits and Residue

I had heard about this stuff from the Scotty Kilmer channel and Engineering Explained on YouTube. I have recently been on a spirit quest to do excellent preventative maintenance on my 2007 Nissan Altima 2.5 S now that I am using it for Uber and Lyft; driving about 1000 miles more a month than I used to. I read recently about the Top Tier rating system for fuel products and I realized with a sink in my stomach that for the past 37000 miles, I have been filling up at the Pilot gas station that is five minutes away from my house and it is a non-Top Tier station. My car had had no problems with the engine or fuel system and still hasn't (knock on wood), but regardless I wanted to do something to try to correct 37000 miles of the gasoline sin of using non-Top Tier gas that lacks the amount and quality of detergents that your Top Tier stations like Shell and Chevron have. I drove my car to nearly empty and pulled into the Shell gas station nearest me. Given that I have a twenty gallon capacity tank, I dumped the entire bottle of the Gumout into my fuel tank and added a fill of gasoline–17.86 gallons–on top of it to mix it in as the instructions said to do. I then drove my car to nearly empty with the Gumout/Gas mixture and just did my second fill up with only a Top Tier gasoline. Because my car had no problems like rough idle, slow acceleration, or what have you to begin with, I cannot say I have "noticed" any difference; but that doesn't mean there wasn't. For seven bucks and being approved by many reputable mechanics, I don't think my money was wasted and now that I am using Top Tier gasoline only I feel better about the longevity and reduced need for repairs my car is hopefully going to have. In summary: My car didn't have anything noticeably wrong that would allow me to observe a noteworthy improvement, but it didn't hurt my car either as far as I can tell; and it has the right cleaners and such for modern fuel injected vehicles. With that uninspiring part of my review over, I can now get on to the really cool NOTICEABLE benefit this stuff had: it was the Dr. Frankenstein to my mower that had been sitting unused too long! I went out to the ranch I manage to do some mowing and to my disappointment, the mower was dead and would not even start. I replaced the battery and was able to get it to start, but the idle was extremely rough and within a minute it spluttered and died. Noticing that the tank was maybe only 10% full, I went and got five gallons of fuel and added about 5 ounces of Gumout as per the instructions for four stroke small motor gasoline. I filled the mower up, shook the mower and let it sit for a minute, went to start it up, and COUGH PUTT COUGH PUTT COOUGHH VROOOOOOOOOOOOMMMMM!!!!! That baby coughed whatever gunky fuel and deposits had clogged up the fuel line or something and fired up! It ran smoothly from startup to intentional shutdown and I knew that I had the Gumout to thank for that. A further benefit of the Gumout too is that it is apparently a fuel stabilizer, so the other 2.5 gallons that is going to sit untouched in the can for up to four months is going to be good to go! All in all, I am pleased with the stuff. Be an educated purchaser: do your research and make sure it is going to be correct and useful for your application, but sometimes it is just fun to use "snake oil" type items like this and just see what happens (when they have been approved for safety by the appropriate agencies when used according to instructions, of course). Thanks for reading my review, I hope it helps you to make your purchasing decision!

I recently had the engine and transmission mounts replaced in my 2006 direct injected Audi 2.0 turbo car at 218K due to idle vibrations and decided to tackle the gas fumes I had been experiencing over the past 5 years in my car while backing up. I tried Liqui Moly Jectron for a week then I came across the DI Jectron version for direct injection engines on the Liqui Moly website I tried the next week. The gas fumes changed from a gas smell to like a sweeter smell with the DI Jectron but on the last 1/4 of tank I got a P0171 code while having to slow down to about 45 mph on a mountain in traffic and then accelerating back up to speed slowly. After clearing the code and adding the Gumout Tune-Up the next morning I tried to duplicate the issue in the same area for two days on the way back from work and the code did not come back. I also noticed less friction in the fuel system with the Gumout product while slowing down and accelerating so I may have has some gunk in the system after the car mostly sat for 2 years during COVID with the ethanol fuel we have in California. The Gumout Tune-Up also cleared up the gas fumes as I am not smelling it anymore and the car is running almost like new. I will continue to use the CRC intake valve and turbo cleaner spray or the Gumout Tune-Up to clean the valves before oil changes and the Gumout Tune-Up every 2 months for the fuel system as I believe these high pressure pump systems need some kind of lubricant in them with the ethanol in the fuel. I may also use 4 ounces of Marvel Mystery oil in the tank again on regular fill ups like I used before COVID to keep the system lubricated. Gumout makes a great product at a great price. ***Update the gas fume smell came back on the 3rd day of Gumout, I am going back to the Liqui Moly DIJectron.****

Been using this for years in my 08 Element. Use 1 per tank full x 3 then one every quarter to 6 months. Gas mileage improvement was fantastic.

Great product but both cans have multiple dents - delivered by USPS and left by garage instead of front door.

I've used Gumout Multi-System Tune Up for both my cars and small engines in my lawnmower and generator. It seems to clean the system and improve performance very quickly. I tend to use it every 7k to 10k miles in my car and with every tank in my lawnmower and generator. I especially like the fact that it is supposed to be a fuel stabilizer as well as clean the system. This has been important to me for my lawnmower and generator. Prior to using any sort of additive in my lawnmower, I had left fuel in the tank over one winter and the next Spring it would not start very easy and would run rough. I added a significant amount of Gumout to the gas and ran it about 5 minutes, though took a while to start was still running rough. Tried it again the next day and the mower worked like new. I can only imagine that the Gumout got worked into the fuel system the day before and it cleaned out the gummed up ethanol overnight. Now I add about 1 oz of Gumout to each gallon of gas for my lawnmower. Since then, it runs perfect with no problems, even when leaving gas in the tank over Winter. For my car, I can definitely notice improvement in performance after using about a quarter tank of treated gas. I am not sure about the level of PEA in the mixture, but it seems to be enough for a mid-size car with an 18 gallon tank. For large vehicles, maybe two can would be necessary. The only thing I don't like about this product is the can. I know it is modeled after the Seafoam container, but it is difficult to use when adding to a car gas tank. Other Gumout products have long neck designs that make adding to the tank easily, it would be nice if this product had that design too.

What else is there to say? This is a great multi-purpose product that has been a mechanic's choice for years. It works exactly as advertised—cleans the fuel system, helps reduce rough idling, and can even improve mileage with regular use. I've used it in both gas and diesel engines without any issues. Definitely a solid value, especially when buying online—much cheaper than what you'll find at most big box stores. If you maintain your vehicles yourself, this is one of those must-have items on the shelf.

This is the only product I’ve found that has enough P.E.A. to clean and prevent the excessive carbon buildup that the Mini Cooper turbo engines are notoriously known for. I run a full bottle through the gas tank just before each oil change and use a third of a bottle in the gas tank at each fill up for maintenance in between oil changes. I have a 2010 Mini Convertible & a 2014 Countryman. Keeps both cars running like new.

I have 2 older cars and they both run pretty well. Sometimes, they seemed to be lagging under load. I ran a can of this Gumout in both cars about a week ago. The lagging stopped and gas mileage improved by about 5MPG in both. One of the cars already has over 500 miles since adding this and seems to be running much smoother. The other one has less than 300 miles since and is doing better but is still on the tank that has the additive in it. One is a Toyota and the other is a Pontiac. Both have over 150K and just needed a little help after plugs and coil packs were changed. The Pontiac was throwing a code that related to the injectors beforehand and that has not happened since adding this and resetting the code. The Toyota has had a phenomena where, after sitting overnight only, it starts and idles fine. Drive it about 1/4 mile to the first stop sign, stop and go to take off and it bogs down pretty bad. It only does it on the first stop. After that, it is fine no matter how many times you stop/start. Until the next morning, when it will do it again. Since adding this Gumout, the bogging down has diminished some but it still does it. So, I am installing a new fuel filter, pump, pressure regulator and, most likely, injectors. Probably will run another can of this through once I do all of that just as a small insurance policy. Does this stuff work? Yes. It helped both cars. It isn't a mechanic in a bottle and I can't expect an additive to overhaul an engine. But, it did up the MPG and smooth out the idle and response in both cars. I believe this Gumout works and works well. I will continue to use it in the future.