Honda hope that their current design of power unit will not need to be drastically changed, majorly improving the odds of delivering a reliable engine to Red Bull in 2019. A previous switch in design for the 2017 season put Honda back in its partnership with McLaren, prompting the British team to eventually switch to Renault.
Red Bull are making the opposite switch to McLaren, ditching Renault for Honda, having grown frustrated with the French marque's inability to keep pace with Mercedes and Ferrari.