F1 teams reach agreement on engines

Formula One moved to end turmoil over engine regulations on Sunday after a weekend of often heated discussions at the British Grand Prix.

Ferrari boss Stefano Domenicali, one of the last to sign, confirmed that a deal had finally been concluded to return to pre-Silverstone set-ups and strategies.

"Let's put it simply," added Renault team principal Eric Boullier: "The debate is closed, please don't reopen it. It took us a lot of energy to close it down."

The governing International Automobile Federation (FIA) had said on Saturday it was prepared to abandon the second phase of a clampdown concerning exhaust gases blown through the rear of the cars if the teams were in unanimous agreement.

The FIA had moved last month to limit the use of engine electronics to ensure teams did not gain an aerodynamic advantage by using systems that allow exhaust gases to flow constantly through the rear diffuser even when a driver is off the throttle.

In Valencia two weeks ago, teams were told they could no longer change engine maps between qualifying and the race -- which would have allowed them to go for extreme settings for the Saturday session before tuning down the engine for race reliability.

At Silverstone, several directives were issued with controversial results, causing teams such as McLaren to complain that the rules were changing by the hour.

One statement on Friday that made allowances on grounds of reliability was seen by Mercedes-powered McLaren to excessively favour Red Bull and their Renault units.

That directive was then withdrawn on Saturday, to the visible fury of Red Bull's Christian Horner who spent an hour in discussions with race director Charlie Whiting.

McLaren principal Martin Whitmarsh, whose Mercedes-powered team appeared to have been badly hit by the changes in qualifying, had called for a compromise agreement.

"Whether people like exhaust blowing or not, it's probably the most equitable situation," he said.

"I think it would be the fairest way. Inevitably in Formula One self-interest sometimes prevails but I think unless we go back to that then this season is going to be fraught with paranoia, feeling of being done to, of being disadvantaged."

Red Bull have started all nine races this season on pole position and had won six of them before Sunday. McLaren had won the other two.

"It (the clampdown) may be worse for other teams but all I can say is that it certainly hit this team, it has hit the performance of our car. I think that is evident from the stopwatch," said Whitmarsh.

"It isn't good to change the rules midway through the year. If you do that, the team that has worked the hardest perhaps to refine that particular rule may well be disadvantaged."