I did not expect to see a difference and it is worth writing that I actually noticed smoother operation, with fewer vibrations and possibly reduced consumption, in combination with general service.

Honestly, I don't know if it works or if what it promises is just a fairy tale. My experience is negative because, even though I have been using this product for over a decade, as well as some other diesel cleaners from Wynn's, my car has shown no signs of improvement in the problems it had regarding fuel (e.g. cuts at high speeds, higher consumption than normal, ignition of the warning "system start/stop fault," check engine, and ESP). In the end, I had to take out and clean the injectors at a specialized workshop, while if the additive did its job, obviously I wouldn't have reached this point. Busted!

I put it in every 4-5 fillings. It really reduces the noise of the machine. It seems to be working in the services that were done in the meantime.