Changes were made for the 2009 season to increase dependency on mechanical grip and create overtaking opportunities – resulting in the return to slick tyres, a wider and lower front wing with a standardized centre section, a narrower and taller rear wing, and the diffuser being moved backward and made taller yet less efficient at producing downforce. The overall aerodynamic grip was dramatically reduced with the banning of complex appendages such as winglets, bargeboards and other aero devices previously used to better direct airflow over and under the cars. The maximum engine speed was reduced to 18,000 rpm to increase reliability further and conform to engine life demand.