Well, initially there was a lot of hype in the comments about fuel additives... I'll share my opinion because I deal with cars to some extent... I'm not a mechanic... I've only done my own research... Initially, this specific product is true in that it offers better fuel consumption, it is true that it cleans the system somewhat... but all these claims that it cleans from the tank go to the injectors... the small debris... they go to the injectors and it may indeed clean them and make them work better, but most of the time, especially if the car is old, the debris that the fuel tank or the entire system may have is usually large, resulting in clogged injectors... fuel additives have the power to clean this system and they can indeed do a specific job, but they don't work miracles like that... the key is to use fuel from a good gas station that you know and that knows you... it's like a butcher shop, imagine... or at least go to a reputable one... in other words, additives in an old car like mine (a 2000 Hyundai Accent) might help the situation if you use the product once or twice, but continuously having such a problem is not good... everything needs its measure in the end...

Car FIESTA of 2018 due to poor quality gasoline had great difficulty starting the engine, especially when I hadn't moved it within 24 hours. Especially one morning, I almost called for a tow...
I tried this specific product after extensive research on its ingredients and it was extremely effective.
I poured the entire container into half a tank and the engine started immediately even when the car had been immobilized for 48 hours. Problem solved!!
For better protection, after the warning light came on with the mixture, the next 2 refills of the tank were done with 100RON gasoline.
If in the future I face the same problem, I will buy the same product again without a second thought!

It does an excellent job. The engine stutters after refueling at a gas station and just before I reach home, the check engine light comes on. I poured it into the tank and took a good ride. The next day, I went to the garage to turn off the light and they told me that it was indeed due to bad gasoline and that the cleaner did its job. Since then, I always have a bottle in the trunk.

It gave me a check engine light due to fuel and the workshop suggested to fix it by having it checked and it worked

It had given me a check engine light due to bad gasoline (I have an OBD scanner) and even though I was clearing the check engine, it kept reappearing! I used the cleaner, cleared the check engine, took a good ride, and it didn't appear again! I recommend it even for use without any issues!

It does a pretty good job. I have used it several times for issues related to injectors. It solves most of the problems. If the problem is serious, like in the case when my car wouldn't start after it turned off unless several hours passed (the injectors were leaking and when it turned off, it would flood with gasoline), two of these in 20 liters of gasoline solved the problem.

If there is a serious problem, put two of these in half a tank and take a good ride. If there is no mechanical damage and it is a pollution issue, they will do the job. If there is no serious problem or just for maintenance, one in a full tank is more than enough.