This is a ECU that was in my Mk3 OBD II Jetta 97. Should fit any Mk3 OBD II 2.0. It was tuned to run the BBM supercharger at 18psi. I would assume it would still work well for most turbocharged or supercharger applications provide they are running the same amount of pressure. The tune was amazing and one of the best parts of the kit as a whole hands down. Note idle was set at 1000 from BBM to prevent stall.