[This review was collected as part of a promotion.] I wanted to try this product even though we keep our truck well-maintained to begin with, so I didn't expect a night-and-day transformation, but the product still delivered a slight noticeable improvement in gas mileage. Every bit helps in this economy. It took a while to start to use this because you need to start with an empty tank and that just isn't something that I do given my trucks tank size and the current gas prices but I chose to use this according to instructions to evaluate it properly. Hence why this is only 4 stars.

Source:

[This review was collected as part of a promotion.] This product is so easy to use and it keeps your car in tip top condition. It keeps your fuel injectors and intake valves clean so your car can keep running for years to come.

Source:

[This review was collected as part of a promotion.] This is a great product! My kids have a 4-wheeler that’s been sitting a while. It was a pain to get started, and when it finally started, it was sputtering and not running good. I followed the instructions on the package and added this to the gas can that I use for the quad. Gumout did the trick! The quad is running much better and it saved me taking it to the shop to have it serviced!

Source:

[This review was collected as part of a promotion.] Pretty simple to use. Allow gas to be almost empty then add the correct amount based on the amount of gallons of gas you’re going to put in your car. Works great on all vehicle types. No messy residue. Just pour and you’re done. Allows my vehicle to run really smooth.

Source:

[This review was collected as part of a promotion.] My dad came over to help me add this to my car. I’m not much a car girl but after a few days of driving I do feel a difference. My car seems to work smoothly. I really enjoy it and will be repurchasing.

Source:

[This review was collected as part of a promotion.] Easy use instructions, added to tank just before fill up for maximum mixing. Great price for an octane booster/cleaner. Plan to use every 1k miles moving forward.

Source:

[This review was collected as part of a promotion.] The car started very fast. It didn’t turn over many times. It just started like it’s supposed to. I didn’t notice much more fuel economy, but I’m driving my car like a race car right now. It feels like a good boost. 

Source:

[This review was collected as part of a promotion.] I'm actually surprised at how well this worked. It for sure made my car idle smoother and not so shaky. I have a 2012 Dodge Grand Caravan and it improved my MPG from 19.6 to 21.2 without changing how or where I drive. It's super easy it use as all you need to do is add it to an almost empty gas tank, then fill up with gas and drive as you normally would. I definitely recommend giving this a try if you want to improve your cars drivability and MPG.

Source:

[This review was collected as part of a promotion.] Used the Gumout in our 2012 Toyota forklift prior to extra work at our house on a building project. I only had to use about 1/3rd of the bottle for our forklift so this will be great to use for other equipment that also needs some TLC around the farm and warehouse. Easy to pour, no harsh smells, and good concentration.

Source:

[This review was collected as part of a promotion.] I had gotten some gas that was questionable. My car was feeling off. This made all the difference. It cleaned the gas tank out and my car is running so smooth. I highly recommend using this. Plus with gas prices this actually will save you money in the long run because you'll get better mileage. Amazing stuff!

Source:

[This review was collected as part of a promotion.] It appears to be a decent injection cleaning device. I couldn’t see a major difference in fuel economy but car idles slightly smoother to I’d say it’s worth it for most applications and users.

Source:

[This review was collected as part of a promotion.] Super easy to use. This bottle treats up to 30 gallon so you might not need to use the whole thing. I put half of it and filled up the tank, and drove it on a highway. I noticed a smoother engine and definitely the octane boost worked. Pairing this with top-tier fuel will help out your car last long. This will make my Bmw engine last as long as a Toyota.

Source:

[This review was collected as part of a promotion.] I’ve been using the gum out fuel injector cleaner to help keep my engine running g smoothly and I’ve been pretty happy with it. It’s easy to add to the fuel tank and I’ve noticed my car runs smoother and responds better. It’s an easy and affordable way to keep you car running at its best

Source:

[This review was collected as part of a promotion.] Amazing product! It was so easy so simple, it made me more confident in taking care of my truck. I love keeping up with the maintenance of my vehicle to make it last longer and have little to no issues. This is a great product to do exactly that. Keeping up with your vehicles maintenance will have it last longer than you. I will definitely be purchasing this product more often!

Source:

[This review was collected as part of a promotion.] I used this on one of my sons dirt bikes since they sit when it’s not desert season. But it helps keep the gas cleaner and protects the engine. I need this for all of the dirt bikes now.

Source:

[This review was collected as part of a promotion.] I have a 13 year old vehicle that I take extremely good care of. This car has a V8 6.2 liter engine that I do everything I can to maintain well. Adding this fuel injector cleaner is part of that. It helps clean the injectors allowing the girl I need to keep this car running at the performance level that I expect.

Source:

[This review was collected as part of a promotion.] So easy to put in and i like that it doesn't cost that much to buy and its good for the maintenance on your car will be buying for my other car cause it was so easy

Source:

[This review was collected as part of a promotion.] The Gumout Supreme Fuel Injector Cleaner is a good product. The instructions were clear and easy to follow. I wish the bottle had marks to tell me how much I used. The instructions state that it's good for thirty gallons, and my tank is not that big, so I had to guess. Once I started driving my car, it worked as it is supposed to. I can't quantify how much it improved my engine, but it seems to do the job well.

Source:

[This review was collected as part of a promotion.] Easy to use this bottle does cover 2 full tanks 30 gallons total. I used half on one fill up and half on another. Put in a 4Runner that’s close to 100k miles so figured anything can help. Reputable brand and product.

Source:

[This review was collected as part of a promotion.] The instructions on this product are a little confusing, but overall I think it is a pretty good product. The vehicle seems to be running with a bit better efficiency and performance, but I am no mechanic, so it can be challenging to gauge.

Source:

[This review was collected as part of a promotion.] Excellent fuel efficiency.Fuel injector works amazing removing additional water in gas tank helped improve fuel efficiency. Used the entire bottle and expected to last treats up to 30 gallons of gas at a time. No ordor excellent quantity for container size snd the consistent in texture is easy to dispense

Source:

[This review was collected as part of a promotion.] I received the gumout supreme fuel injector cleaner complimentary for an honest review. The cleaner treats 30 gallons of gas and is easily added to gas tank.

Source:

[This review was collected as part of a promotion.] I had a good experience to come out supreme. I liked that the bottle had a fuel, injector cleaner and octane booster all in one product. It was easy to put in my fuel tank. I didn’t spill a drop. Fortunately, one bottle was the perfect amount for my fuel tank. Overall, I would buy this again.

Source:

[This review was collected as part of a promotion.] “This stuff is like a little pit crew in a bottle Super easy to add to the tank, and I noticed the engine seemed to run smoother afterward. Definitely a handy fuel-system sidekick to keep in the garage!”

Source:

[This review was collected as part of a promotion.] I like using Gumout on my antique vehicles. These tend to sit for extended periods of time, and Gumout Supreme helps keep gas fresh and things lubricated during that time.

Source:

[This review was collected as part of a promotion.] Would recommend this product. 3 weeks since adding this product in my vehicle and I kept a log detailing the miles driven and fuel cumsumption. I have seen in increase in MPG averaging in the ballpark of .8 - 1 MPG. I also had a slight tic in engine noise that has gone away. Very happy.

Source:

[This review was collected as part of a promotion.] I used this Gumout fuel injector cleaner and octane booster in my motorcycle. It was idling a bit rough and it was suggested for me to run a fuel injector cleaner through a tank of gas. After using it, the idle smoothed out. Just one ounce treats a tank of gas (3 gallons). So, I can run 10 tanks of gas with one bottle of Gumout. I will continue to use this to keep my fuel system clean and to boost the octane of my fuel.

Source:

[This review was collected as part of a promotion.] This Gumout Supreme Fuel Injector Cleaner + Octane Booster is absolutely amazing! This is great to put in your vehicle right before winter. There's no smell so you don't have to worry about it stinking. It's very easy to use which is great. Just put it in your gas tank before you put in 30 gallons. Helps with maximum performance and makes your vehicle feel new. Overall this is definitely a must have for any vehicle especially the hemi.

Source:

[This review was collected as part of a promotion.] I have a 2016 Chevy equinox used the gum out supreme fuel, injector cleaner, octane booster worked as the directions said very satisfied with the product definitely will buy this product again 

Source:

[This review was collected as part of a promotion.] This fuel injector cleaner is simple and effective. All you have to do is poor this cleaner before you fill up with fuel, and you let it do it’s thing. This product will clean your fuel injectors with little effort, great cleaner.

Source:

[This review was collected as part of a promotion.] First time using this product on my vehicle. Put it in a week ago, not sure if there’s supposed to be a noticeable difference when driving. My vehicle seems to be running smoothly though. So I guess it’s a win!

Source:

[This review was collected as part of a promotion.] I’m a little disappointed that the unit is meant for 30 gallons while the majority of vehicles have fuel storage under 20 gallons with that in mind you have to adjust the ratio of what you put in your car when it’s empty. I thought that was a big drawback besides that I feel like my fuel economy is doing a little bit better and I feel more comfortable that my vehicle has slightly cleaner fueling. 

Source:

[This review was collected as part of a promotion.] As vehicles age we often forget routine maintenance. The quality of the fuels we get can sometimes lead to build up and poor performance. So with wanting the efficiency of the fuel system to work this is a great product to help reduce the amount of build-up that can be created over time. This product can help the consistency and volume from the overall fuel system.

Source:

[This review was collected as part of a promotion.] I really didn't think that much of this type of thing but I haven't paid as much attention to my car lately but once I added this I did notice a nice difference in performance. In my opinion it rides smoother and sounds better. Get you one and see what it does for your car. The containers are easy to spot and easy to understand what it can help with.

Source:

[This review was collected as part of a promotion.] This Gumout fuel injector cleaner and octane booster is a no brainer when it comes to your car’s maintenance. We use it in both of our cars during fills and it helps keep the fuel injectors and other components running as smooth as possible. It comes with enough to treat up to 30 gallons and the bottle is slim and easily stored due to its slim bottle design. People easily overlook things like your fuel injectors and intake valves when talking about preventative car maintenance and this all in one solution helps keep everything clean and working at its best.

Source:

[This review was collected as part of a promotion.] Added it in hard to tell any major difference in performance. Did notice an average of 1mpg more compared to typical gas mileage that I get in my truck.

Source:

[This review was collected as part of a promotion.] I’ve been using Gumout Supreme Fuel Injector Cleaner + Octane Booster as an easy way to help keep my fuel system clean and my engine running smoothly. I like that one bottle does more than just clean the injectors—it also provides an octane boost and is designed to help with knocks, pings, and rough running. It’s incredibly simple to use: just add it to the gas tank when filling up. One bottle treats up to 30 gallons, so it goes a long way depending on your vehicle. I also appreciate that it combines cleaning and protection into one product instead of needing multiple additives. For an inexpensive and easy addition to regular vehicle maintenance, this is definitely something I’m happy to keep in the garage.

Source:

[This review was collected as part of a promotion.] My husband used this on his car (14 year old four cylinder with ~160,000 miles on it) according to directions and says his engine noticeably ran better and acceleration is working better than it has in years. It also has multiple treatments in the bottle despite it looking like a single treatment bottle. We have noticed his gas gauge is acting up since using it, but given the age of the car we think that’s probably coincidental. He did find the liquid difficult to measure and there is no included measuring system which is why a star has been knocked off, but otherwise it works great.

Source:

[This review was collected as part of a promotion.] We have older vehicles with high mileage and after using this, we could tell a difference in how our vehicles were running. I’d definitely recommend

Source:

[This review was collected as part of a promotion.] Got this product in the mail and couldn't wait to use it. My car is a couple years old now, and can definetly use some better gas mileage. Product is very easy to use. Just pour it in, fill up your gas tank and watch the results.

Source:

[This review was collected as part of a promotion.] Solid product to ensure your engine functions on all cylinders (pun intended). I like to use the Gumout products regularly for my F150, especially since I don't use the higher octane 91 regularly and using the Gumout helps frequently to breakdown the build up from the lesser fuel. Using the product is easy, twist the cap and pull off the seal and add to an empty tank. Easy.

Source:

[This review was collected as part of a promotion.] Works great on new and old engines and really gives it a good clean! It appears to have given my engine more power and is safe to use and all engines.

Source:

[This review was collected as part of a promotion.] I noticed an improvement in my gas mileage almost immediately after using this fuel injector. it helps get your car running smooth and extends its life!

Source:

[This review was collected as part of a promotion.] I wanted to test out Gumout Supreme Fuel Injector Cleaner and Octane Booster fairly, so before I added it to my fuel tank I wanted to control other maintenance variables, so I did a fresh oil change and inflated tires to factory recommend levels. Prior to adding the product, my 2020 Mazda Cx5 was averaging 26 mpg under mixed driving conditions. Just one week of running this through a full tank of gas my average climbed to 27.5 mpg. A solid improvement in my opinion. Just as noticeable was the throttle response. Accelerating felt smoother and snappier off the line. For a pour in additive, it delivered measurable results immediately. This stuff works in any gas engine vehicle and one bottle treats 30 gallons of gas. I plan on using this in conjunction with every oil change.

Source:

[This review was collected as part of a promotion.] I recently added Gumout Supreme fuel injector cleaner + Octane Booster to my 2017 nissan altima. Ive noticed that my car runs smother. I really think this stuff actually works. My car was sounding a bit rough and after using this product it sounds better.

Source:

[This review was collected as part of a promotion.] This was very easy to use. The bottle fit right into my fuel tank. My car seems to run smoother. I would occasionally have some sputtering, but this seems to have fixed my issue.

Source:

[This review was collected as part of a promotion.] This fuel injector cleaner works really well. It is simple to use. Nothing to mix and my engine is running a lot smoother.No more knocking sound. This really made a difference .

Source:

[This review was collected as part of a promotion.] Easy to use convenient to add to the fuel tank.After using it,my car seemed to run smoother and the engine performance felt better.The bottle is easy to pour and the instructions are simple to follow.I use occasionally,and the results seem to last.My car also starts smoothly.The effect seems to last between uses.The product has good durability and provides lasting results.

Source:

[This review was collected as part of a promotion.] I put this in my car is was having sluggish issues and it seemed to help out my car runs smoother and sounds better. I definitely will buy this in the future.

Source:

[This review was collected as part of a promotion.] Great product. My husband used it on his older work truck. He noticed a difference after the one bottle and wants to do it as regular maintenance now.

Source: