Tested on the multiple intake of the Opel Corsa. With the proper care and according to the manufacturer's instructions, the results are quite satisfactory.

Whatever I write is not enough. In a Suzuki Grand Vitara 2008 diesel, the differences in noise, consumption, and pulling power are like day and night. I couldn't believe it unless I experienced it myself.

From the first use, there is a significant difference in the car's performance when carrying a heavy load of 2,000 to 2,500 RPM. Previously, it used to rattle while the injectors were from the box, but now it runs smoothly. I bought it in combination with the Liqui Moly system cleaner. Once I add it and drive a few kilometers, I will let you know my impressions

For cleaning the first part of the intake, it's great. Unfortunately, it does very little for the inner parts, meaning multiple intakes and valves. If used regularly (e.g. during every service) for maintenance, it's perfect

Personally, I noticed a significant difference in the behavior of the engine and fuel consumption from the first time. I had never used anything similar before.

Amazing product.
Applied to Fiat 1.3 multijet (aka 1.3 cdti, 1.3 jtdm-1), I applied it by removing the throttle collar and inserting the tube deep and adjusting it back and forth. Then you need to clean the map because it bends it.
The problem is how to keep the RPM steady. For me, you need an assistant in the car to tell him to try to keep the RPM steady at 2000 so that you can spray for more than 1 second without the vehicle over-revving. It does a good job with a lot of patience. But as long as the EGR is working, you will be fighting. So before every oil change, use one of these.