Renault has made significant progress with the reliability and drivability of its engine over the winter, which will translate into real performance on track, according to chief technical officer Bob Bell.
Renault has been several steps behind its rivals ever since the introduction of the V6 turbo hybrid regulations in 2014, but has upped its investment in Formula One this year by setting up its own works team. The team faces a big challenge over the coming years as it addresses the shortfalls of the engine department in Viry Chatillon while bringing the former-Lotus factory in Enstone back up to speed, but Bell said the winter's work on the V6 turbo had been positive.
"The engine in the works team has been great," he said. "We had one issue early in the test where we changed a turbo, but it wasn't a huge surprise to us and it was a known fault that won't be there for the Race 1-spec engines. But other than that it has been great, we haven't had those troubles [experienced in the last two years].
"Viry Chatillon has done a great job over the winter in terms of making the engine drivable, and there is real performance in that that doesn't necessarily show in headline figures. They've got reliability and they've got a big step forward in where the engine actually delivers."
Asked where Renault had made gains, Bell said: "I'm not at liberty to discuss the details of the changes, but suffice to say there are many.
"To put that in context, the token system that is there to help performance convergence and reduce cost hasn't held us back in any way and we've been able to do all the things we wanted to do.
"Viry has looked hard at all aspects of the engine to find gains and there are gains spanning the whole plethora of components of the system, from the electrical machine to the internal combustion engine."