This work addresses the problem of controlling unknown and time varying plants for industrial applications. The concept of “plug-and-play” was pursued using control algorithms that auto-adapt their control parameters in order to control unknown and time-varying plants. Self Tuning Controllers (STC) with PID form were studied and tested on a real process setup. The setup is composed of two coupled DC motors and a variable load. Controllers’ performances were compared in order to distinguish which controllers perform better, which are easier to set up, which have a better initial response, and which enable faster reaction to plant variations and load disturbances.