Formula One engines must last twice as long next year and be reduced in capacity from 2006 to cut speeds and improve safety, the sport's governing body said on Friday.
The International Automobile Federation (FIA) confirmed controversial regulation changes, which had been presented to teams in draft form in June, at the season-ending Brazilian Grand Prix.
It said in a statement that engines must last for two complete events, instead of one race weekend, with any driver requiring a replacement docked 10 places on the starting grid.
From 2006, engine capacity will be reduced from 3.0 litre V10s to 2.4 litre V8s despite opposition from three manufacturers Mercedes, BMW and Honda.
However, small independent teams will be allowed to continue with existing 3.0 litre V10s in 2006 and 2007, providing they have restricted output.
FIA president Max Mosley has pushed the rules through on safety grounds, arguing that more power equals more speed and more speed means more danger. Cutting costs and making the sport more exciting was another factor.
Teams will also be limited to one set of tyres for qualifying and the race, forcing them to use a harder compound that should lead to reduced cornering speeds, while aerodynamic changes will also come into effect.
It's what we expected and I'm completely in favour, said Renault's Flavio Briatore.
While all teams agreed on the aerodynamic and tyre regulations, they were divided on the engine measures and twice failed to vote by a required 8-2 majority in favour of any of three alternatives presented to them by the FIA.
That failure allowed the FIA to impose the measures.
Mario Theissen, motorsport director of Williams partners BMW, said the carmaker would discuss the situation with Mercedes and Honda.
All of us agree on engine life extension ... but the main issue for us is the three litre V10, he said.
Honda's Ottmar Szafnauer said the Japanese manufacturer, partners to BAR, were opposed to restrictions imposed on the weight and centre of gravity of engines in 2006.
We want the engine formula to be open so that we can differentiate ourselves one from the other, which makes the sport interesting for us and is one of the reasons we are here, he said.
The FIA have the right to institute these restrictions but they don't take effect until March 1, so we hope in the time between now and then to come to a compromise that is a bit less restrictive than this.
I think the first thing to do is fight this in every way you can, he added, when asked how the measures might affect Honda's commitment to the sport. Reuters