Red Bull's Formula 1 future post-2016 is far from certain according to team owner Dietrich Mateschitz, with the Austrian billionaire once again threatening to quit the sport if the engine situation doesn't change.
Red Bull came close to walking away last season after it fell out with engine supplier Renault, before a late deal to continue using the French marque's power units, rebranded under the Tag Heuer brand, secured the team's place on the grid.
That deal is however for a single season, and with both Ferrari and Mercedes unlikely to offer its engines to the team, Red Bull could find itself in the same position – should they stay or leave?
The latter is entirely plausible according to Mateschitz, unless something changes.
"Formula 1 is not the Tour de France," he told Speedweek. "We are too good to be domestiques," he added in reference to riders who support the team leader.
"If we are not competitive from an engine point of view, we will leave," the 71-year-old warned. "For sure we don't want to spend the next five years fighting for P5. We want to be P3 behind the manufacturers' teams. We should win the fight against the customer teams of Mercedes and Ferrari."
Speaking about the season ahead, Mateschitz wouldn't be surprised if Toro Rosso – with its 2015-spec Ferrari engine – are quicker in the opening half of the season.
"The car is great," he said of the STR11. "I wouldn't be surprised if Toro Rosso were on the same level or even faster than Red Bull in the first races.
"Toro Rosso is supposed to achieve something between fourth and sixth in the constructors' championship. But this is what we have hoped for every year so far."