Christian Horner believes Formula One's regulation changes and bigger cars for 2017 caused correlation problems with Red Bull's windtunnel which set the team's programme back by around two months.
Red Bull -- renowned for its strengths in aerodynamics -- was tipped to become Mercedes' direct challenger for the 2017 championship following F1's new regulation overhaul ahead of the season, though it failed to crack the aerodynamic-led changes and instead lagged behind Mercedes and Ferrari from winter testing.
The quadruple world champions fell well short of its main rivals in the opening races of the year as it soon transpired the team would be unable to mount its first title challenge since 2013.