Toro Rosso are looking to change to Renault engines in 2014 in order to take advantage of their relationship with Red Bull.
At present reigning World Champions Red Bull use Renault engines while Toro Rosso, the junior team, are powered by Ferrari.
However, the Faenza-based squad is keen to swap suppliers, which would allow them to incorporate Red Bull's gearbox into their own car.
"We are in negotiations with Renault and then we will see. No contract has been signed so far," said team boss Franz Tost. "This for sure would be an advantage because if you are racing with a Renault engine we would have the same gearbox as Red Bull, because this is possible from the regulation side.
"We will use the synergies that the regulations will allow us to do."