Until the end of 2010, Formula 1 engines are 'functionally stabilised', with only minor changes being allowed from the engines that will race this year. They are naturally aspirated, 2.4-litre V8s, currently with a rev limit of 19,000rpm, and they must weigh at least 95kg. They already produce in excess of 750bhp.
The 2007 cars themselves are very similar to the 2006 machines, the key change being the exclusive use of Bridgestone tyres. In 2008 cars will become significantly wider, up from a maximum of 1800mm to a minimum of 1950mm (rising again to 1980mm in 2009), with a maximum width of 2000mm. The minimum total weight of the car (including driver) falls from the current 600kg to 550kg in 2008, and then rises again to 605kg in 2009.The two main changes already approved for 2009 are the imposition of a maximum downforce limit of 12,500N and the introduction of Kinetic Energy Recovery Systems (KERS). KERS, as currently defined, can only be connected to the rear wheels, and must deliver no more than 400kJ per lap at no more than 60kW (80bhp), which effectively means a burst (or bursts) of extra acceleration totalling less than seven seconds per lap. The braking power of a KERS is also restricted to a maximum of 60kW. While the 60kW limit on extra accelerative power may be prudent and sensible during the first season of a new technology, the other limitations seem to run counter to Formula 1's new focus on fuel efficiency and relevance to road vehicles. Even if these limits remain in force for 2009, it would seem sensible to remove, or at least raise d them for 2010.