Certain engine additives work by cleaning fuel injectors and intake valves, reducing friction, preventing fuel degradation, etc. Their effectiveness depends on the product's quality, how it's used, and vehicle condition. Which, if any, additives do you use or recommend .
A few of my favored: Techron , Sea Foam motor treatment, Rislone, and Lucas oil/fuel Treatment. Obviously Sta-Bil is a given !

 

I used it when I first purchased my SRT6. I know this will be controversial, but I have used it on a few cars and have never had a problem. The first step is to do an engine flush, and then you add the CERA TEC Engine Oil Additive. After that, with every oil change, you use step 2:6 Cylinder Additive Kit (Step 2) - Liqui Moly. This includes an oil additive and a fuel system cleaner.

I found the SRT ran better and cleaner.

As I have stated, I used this on my 2013 S4, 2011 C300, Mazda Speed 6, and my new to me Cadillac CTS4.

 

When I use a fuel additive, I always use the Techron product in the Crossfire. Somewhere I remember coming across an article that stated M-B recommended Techron fuel system additive if one was to be used.

I do know the SeaFoam product is used by some M-B Service Centers to clean the throttle body. This is accomplished by removing the vacuum line from the Power Brake Booster that come from the Throttle Body intake. Then the SeaFoam product can be sucked into the Throttle body at a slow rate (thumb probably partially blocking the vacuum line) without stalling out the Engine. There is a posting somewhere on this Forum about how to perform this cleaning using SeaFoam. FOUND IT!

 

I have noticed a little better engine performance after adding SeaFoam to the gas tank