This computer is the best accessory you can buy for your BMW E90 320d. The computer will boost your horsepower from 177PS to 220PS. Torque will increase from 350Nm to 450Nm. These are actually conservative figures. I also recorded between 12% and 15% better mileage. On the highway at 140kph I regularly attained less than 5l/100km. The extra torque cut my 0-100kph time from 7.9 sec. to 6.8 sec. This computer plugs in with three connectors and takes less than five minutes to complete. This will put a big grin on your face for sure.