Will Red Bull Racing take the plunge and go with Honda in 2019, or will it stick with Renault and extend what has been a rocky relationship over the past dozen seasons?

That's a question that's been in the air ever since Honda's move to Toro Rosso was confirmed last September.

From the start, it was abundantly clear that Honda was auditioning for an eventual move to Toro Rosso's big brother - the team with which it could target world championships.