Red Bull and Lotus's engine suppliers Renault have vowed to conduct an investigation into why the alternators on Vettel and Grosjean's cars failed.
French engine maker to conduct investigation into double failure
Renault have taken the blame for the alternator problems that cost engine customers Red Bull and Lotus chances to win the European Grand Prix.
The French manufacturer, which also supplies its V8 engines to Williams and Caterham, vowed to conduct a full investigation into the problem after failed alternators first ground the race-leading Red Bull of Sebastian Vettel to a halt and then Romain Grosjean's second-placed Lotus.
Both teams swiftly identified the offending part on their respective cars and Renault later confirmed that while Vettel's had simply overheated, causing the engine to shut down, Grosjean's had failed and caused the fuel pump to stop working.
Renault said in a statement: "We do need to hold our hands up and apologise to both Red Bull and Lotus on the problems on the sister cars of Sebastian and Romain.
"Both suffered alternator failures, although it seems for different reasons at this point in time.
"Sebastian's overheated and the engine shut down, while Romain's alternator failed and the electrical power to the engine stopped.
"We will of course thoroughly investigate the reasons for this when we get the units back to Viry to try and ensure that Red Bull and Lotus, plus our other partners, do not have the same issue in the future."
Renault added that they would also be investigating why the KERS unit on Heikki Kovalainen's failed during the race.
"Similarly, we will also work to understand the reasons for Heikki's KERS failure - there is a lot of work to be done between now and Silverstone but we have a strong team and resources in the factory," the company added.
