Royal Purple Max-Clean Fuel System Cleaner and Stabilizer 11722 20 Ounce

It takes the engine shutter out of my 2018 3.5 echoboost. Seems to work great so far and adds a little bit of mpg also

Great fuel injector cleaner. Royal purple is the best product you can use on your vehicle.

I seems to work very well. I tried it out and noticed immediate results. The car appeared to accelerate and run at much smoother intervals.

First off, let me start by saying: Wow, what a product. Good job, RP. With that being said, I purchased this product for my 2013 Civic Si - which I've been tuning for a a while now. I noticed that with a tune and modifications, it lost some MPG and I was barely seeing 260 miles per tank. So, I asked myself, "Is the extra power from the tune worth the loss in MPG?" I thought there had to be something out there to help. I tried several fuel system cleaners over the past 6-8 months, I used one every month (or four tanks) and they all seemed to do very little. I came across Royal Purple Max-Clean Fuel System cleaner - wow, what an improvement. I run on Shell's Nitrogen Enriched 93 Octane gasoline. It is only getting more and more expensive, so this is something I wanted to try in order to help save money in the long run, and I think I will. My first tank using RP's Fuel System Cleaner had 304 miles traveled, and I wasn't driving conservatively. Not only gas mileage, but performance peaked as well. When we tune, we see everything the computer in the vehicle records and we noticed a 2% top-end increase in performance at high RPM - that's incredible for less than $20. But the question remains, "how long will this last?" Would I recommend this product? Most definitely. This container is large enough for two tanks on my Si (it's a small 13 gallon tank). Remember to follow the instructions - don't just dump this stuff into your gas tank. You should see an improvement about half way through your first tank. Just keep an eye on the MPG. From what I can tell from data logs and tuning, this product should only be used once every 3-5 months (or 8-12 tanks of gasoline) but varies depending on driving style. Using too much of anything isn't good. So, why after all of that, did I only give this product a 4 out of 5? I gave it 4 stars out of 5 stars because of the container and its design. You can't just dump this stuff in some gas tanks on newer vehicles without making a mess. I did not have a funnel that fit into my gas tank, so I was forced to buy one in order to use this (another $5~ or so). My point being: You shouldn't have to purchase additional items to be able to use this. Other than that, it's a great product and definitely worth the investment. I'm not going to say you will see a huge improvement, but it does help. How much depends on your driving style, your vehicle, and what grade gasoline you use. EDIT 1: One month after use: So, it has been about 3 tanks since I've used this stuff. I have noticed that the first two tanks, MPG stayed up there, and now is beginning to decrease slightly. Although, my driving patterns aren't 100% consistent, so it's difficult to tell for certain. I do believe that this product works, and still recommend it once every 3 months or so. EDIT 2: (July 15th, 2015): So, it has been well over a year. I use this product at least once per season on my Si. Every time I do so, I feel the improvement. Still highly recommended. The improvements seem to last about a few weeks (or few tanks). I'm not sure about mixing other RP gasoline products (e.g. Max-Boost). Royal Purple products are the ONLY products that go into my vehicle.

Worked perfectly

Excellent fuel treatment to clean carbon buildup off the Valves and Cylinder heads. Highly recommended by professionals in video comparisons. This won 2nd place but does almost as well as the 1st place product that required several steps. I am happy with it. Made my 2024 Honda CR-V and wife’s 2013 Honda Accord run and idle better. Son also claimed his 2019 Ford Fusion was helped also.

Product as advertised

Likely decent product as I'm a user of RP products over the years. This was the most convoluted packaging design that I have seen. The fragile pull tab on the seal immediately broke. I forced a screwdriver through the seal and it was so tight that the entire cap assembly came loose and I ended up using a funnel of my own (with the assembly gone, the included funnel was of no use). A simple chore turned messy for no good reason. Product spilled and wasted. Whoever devised this needs a short lecture....

Really love this product, it makes my toyota fortuner run very smoothly, less knocking sound of engine, giving better performance and fuel efficiency improved.

Fantastic product.

息つぎが改善され吹け上がりが良くなった。 アイドリングが少し安定してる。 キャブ車におすすめです♪

Pues parece que si funcionó bien, hay muchos productos como este sin embargo si noté que la camioneta recobró cierta potencia. Lo recomiendo

This product gave me 11% extra mileage but it didn't remove check engine light.