Renault F1 executive director Marcin Budkowski says the manufacturer's all-new engine for 2019 is looking "very promising", although he insists that the quest for the right balance between performance and reliability is ongoing.
Renault's Viry-Châtillon engine department made slow and steady progress last year, but power was still at a deficit relative to Mercedes and Ferrari.
In a bid to inch closer to its front-running rivals, Renault has engineered a new power unit for this season, and Budkowski has cast a positive outlook in terms of its performance.
"We’re very optimistic on the engine side," Renault's said executive director told Crash.net.
"But the engine is like the chassis side - it’s never finished until you close the engine that goes to the first race.
"It is very promising in terms of performance but we still have to cross the t’s and dot the i’s in terms of reliability and durability etc, which we are doing now in Viry-Chatillon."
Just three weeks from the start of pre-season testing in Barcelona, Budkowski said that engineers are still fine-tuning Renault's new unit in order to strike the right balance between performance and reliability.
"We are still doing work on the engines that will start the year, and in the end performance and reliability is a trade-off," he added.
"You can extract more performance from any engine but it might not last the number of races, the number of sessions you want it to.
"So we will have to see where that cursor stops in terms of performance versus reliability. But we are optimistic."
Gallery: The beautiful wives and girlfriends of F1 drivers
Keep up to date with all the F1 news via Facebook and Twitter
