Leading teams Ferrari and McLaren expect engine reliability to play the most important role in deciding the fate of the Formula One championship after yesterday's eventful European Grand Prix.
In the inaugural race on Valencia's street circuit, Ferrari's Brazilian Felipe Massa drove superbly to claim an unchallenged victory but his team mate and defending champion Finn Kimi Raikkonen retired after blowing his engine.
It was the second engine failure in successive races for the usually ultra-reliable Ferrari and left them mulling over mechanical issues, while McLaren did not have to fit a single spare part to a car during their three days on the track.
"Unfortunately, we suffered with a reliability problem which lost us precious points. Now we have to find out what happened in yet another engine failure and then decide how to react," Ferrari team chief Stefano Domenicali told reporters.
"Clearly what happened is serious and we will have to do all in our power to make up for the ground we have lost through reliability problems in the coming races.
"Now we must continue to push to the maximum to develop the car and improve reliability in order to be as well prepared as possible for the forthcoming races."
His technical chief Luca Baldisserri was equally as forthright.
"We have a great potential from both the team and the car, capable of putting us in front of everyone else, but if not all the elements are operating at their optimum, then we are throwing away precious points that could cost us dear," he said.
"We must work to remedy these problems and that's what we have to do now."
After the unique challenge of a new street track, the championship moves on to the traditional power circuits at Spa-Francorchamps in Belgium and Monza in Italy, where engine reliability will be tested to the maximum.
"The most positive element for us was that the boxes containing our spare parts were kept closed all weekend," said Norbert Haug, sporting chief for McLaren engine suppliers Merecedes-Benz.
"We didn't need to fit a single replacement part throughout a race weekend that everyone thought would be full of crashes," he added.
"Now we can work hard for the final third of the season, which begins with the back-to-back races at Spa and Monza, two particularly challenging circuits that will put maximum stress on the engines."
Haug's words echoed those of team chief Ron Dennis, who admitted the team had opted for the strategic goal of seeing Briton Lewis Hamilton finish second behind Massa.
"In my view, it's pretty clear that if Lewis had qualified with the same level of fuel as Felipe, he'd probably been able to control the race front, but the nature of the circuit dictated that it was going to be difficult for him to overtake," Dennis said.
Despite Hamilton's illness and neck problems, McLaren earned enough points to cut into Ferrari's lead in the constructors' championship and see the 23-year-old Englishman extend his advantage in the drivers' series.
With six races remaining, Hamilton leads on 70 points to Massa's 64 and Ferrari have 121 to McLaren's 113.