Wolff rejects 'irresponsible' engine cost war talk OXFORD England (Reuters) - Mercedes motorsport head Toto Wolff has played down Red Bull's threat of an engine development spending war in 2016 by saying the major car manufacturers agree on the need to keep costs down. Speaking to reporters on Thursday, the Austrian made clear that Mercedes and Red Bull's engine suppliers Renault were closely aligned in their strategy for the V6 turbo hybrid power unit and in regular dialogue. He added that any return of the old V8 engine was a non-starter and manufacturers like Mercedes would leave the sport if it were to happen. Nobody can really be in favor of an all-out engine war in 2016. No serious company would allow that to happen," said Wolff. And none of the current engine suppliers can allow that to happen because costs would be escalating totally out of control. It's irresponsible. Red Bull principal Christian Horner told reporters in Brazil last weekend, after manufacturers failed to agree any changes to the 2015 regulations, that the sport could be forced into a spending war as a result. Red Bull and Ferrari want the rules to be relaxed to allow them more development time to catch up with Mercedes, who have the dominant engine. Mercedes have offered a compromise solution, that has been rejected by their rivals, and the result has been deadlock with any changes for 2015 requiring unanimous agreement. However, technical changes for 2016 can be pushed through on a majority vote. Wolff indicated Horner was speaking for Red Bull rather than Renault and said Mercedes would be "very vocal" if the gloves came off for 2016. "Renault and Mercedes are aligned on their strategy on where the engine should be," he said. "On a motorsport level, between the two departments Renault sport and Mercedes motorsport, we are fully agreed," added Wolff, who said the two manufacturers would have more discussions in Abu Dhabi next week. The Austrian pointed out that Renault had made the new engines a condition for them staying in Formula One "so all the other things which are being discussed are just funny. "If we dropped the current format I can guarantee for sure that Renault and Mercedes would not be interested in supplying any other power unit because of the stability and sustainability of the sport and the road relevance of the hybrid technology," said Wolff. We should be promoting the technology of those engines.