The BMW X3 2.0 d (E83 / E83N) Turbo Upgrade ECU tuning files are created by a team of experts and car enthusiasts who have been working in this field for many years. They have dyno tested the BMW X3 2.0 d (E83 / E83N) Turbo Upgrade ECU tuning files to ensure that they are high quality and increase power up to 20% while maintaining the best fuel efficiency.