Red Bull boss Dietrich Mateschitz is confident his Formula One team can close in on world champions Mercedes this year, but says Ferrari is an "unknown".
Red Bull finished a distant second in 2016, but new aerodynamic regulations have the potential to reshuffle the competitive order this year. The new rulebook should play to Red Bull's strengths in chassis design, but Mateschitz says the key to catching Mercedes will still be the performance of his cars' Renault power units.
Renault made significant progress in 2016 after working closely with Mario Illien's engine company and with more big changes coming from the French manufacturer in 2017, Mateschitz is eyeing a title battle with Mercedes.
"Renault brought new, ambitious and, above all, competent people for 2016, and there was much progress with Illien," he told Salzburger Nachrichten. "I expect this year's engine to be powerful enough that we can get closer to Mercedes.
"We want to be absolutely competitive by the middle of the season. However, Ferrari is still the unknown. Our driver pairing of [Daniel] Ricciardo and [Max] Verstappen is a clear plus for us."
Mateschitz said Formula One is in need of a tight battle between its top teams this year.
"The popularity of Formula One stands and falls with the competition at the top. Motorsport is good when the top teams are close together. A fight for third and fourth place is not enough.
"The cars have to become more extreme again, which has already been initiated for this year. [Unfortunately] the many stupid penalties for drivers remain, which no fan understands anymore."