Feb.9 (GMM) Renault is a secret to Red Bull's recent success in Formula One, the French carmaker claims.
The common perception, however, is that the energy drink-owned team has dominated the sport in recent years despite Mercedes-Benz actually supplying a more powerful 2.4 litre V8 engine to Red Bull's rivals.
"The Mercedes engine is indeed about 15 horse power more powerful than ours," confirmed Renault Sport F1's Jean-Francois Caubet.
"But in terms of driveability and fuel economy, it is our engine in front. So when it comes to the bottom line, we are a little bit better than Mercedes," he claimed to Germany's Sport Bild magazine.
The most crucial factor, Caubet claimed, is the engine's fuel economy amid the backdrop of the recent ban on in-race refuelling.
"Because our consumption is lower, Red Bull can start the races with 15 to 18 litres less petrol in the tank than the competition," he said.
"That makes a big difference."
Another factor is Sebastian Vettel's driving, he agreed, with the back to back world champion having a "very fuel efficient" style, and being "extremely interested in the data".
"They are both key factors when the driver wants to use the engine perfectly," said Caubet.