<P> In 2009, constructors were allowed to use kinetic energy recovery systems (KERS), also called regenerative brakes . Energy can either be stored as mechanical energy (as in a flywheel) or as electrical energy (as in a battery or supercapacitor), with a maximum power of 81 hp (60 kW; 82 PS). Four teams used it at some point in the season: Ferrari, Renault, BMW, and McLaren . </P> <P> Although KERS was still legal in F1 in the 2010 season, all the teams agreed not to use it . KERS returned for the 2011 season, when only three teams elected not to use it . For the 2012 season, only Marussia and HRT raced without KERS, and in 2013 all teams on the grid had KERS . From 2010 to 2013 cars have a regular power of 700 - 800 hp . </P> <P> The FIA announced the intention to change the 2.4 - litre V8 engines to 1.6 litre V6 turbo engines for the 2014 season . The new regulations include multiple energy recovery systems and fuel flow restrictions, to attract more commercial partners . </P> <P> The new formula reintroduced turbocharged engines, which last appeared in 1988 . These have their efficiency improved by turbo - compounding and introduce more energy recovery systems--with power to be harvested from the brakes and exhaust gases . The original proposal for four - cylinder turbocharged engines was not welcomed by the racing teams, in particular Ferrari . Adrian Newey stated during the 2011 European Grand Prix that the change to a V6 enables teams to carry the engine as a stressed member, whereas an inline 4 would have required a space frame . A compromise was reached to adopt V6 turbocharged engines instead . The internal combustion engines are limited to 15,000 rpm, but rarely exceed 12,000 rpm during Grand Prix due to the new reliability and fuel flow restrictions . </P>

What engines do they use in formula 1