In BMW engine tuning, there are several easy ways to increase power and speed. One of the easiest ways to increase speed in a BMW automobile is to switch the electronic control unit, or ECU, chip. A new chip may increase performance and speed, but reduce fuel economy and cause the car to fail emissions tests. Upgrading certain components like mufflers is an easy way to improve the car’s performance, as well. Simply making filter or transmission adjustments can impact the car’s performance. Also, installing lighter wheels and thicker tires can increase the performance and safety of a BMW vehicle.