F1 has introduced some of the biggest rule changes in its history, with cars now smaller and more environmentally friendly. The drag reduction system (DRS) has been replaced with overtake mode, which allows drivers to generate extra electric energy when they are within one second of the car ahead. However, there is concern within F1 about the increasing energy management and potential impacts on driving. The new cars and regulations have been met with mixed reviews, with four-time world champion Max Verstappen calling them "like Formula E on steroids".