After a difficult, incident-filled start to the 2013 season, the 36-year-old Australian knows he has to deliver consistent strong performances to ensure he stays at the top.
Honda president Takanobu Ito said "McLaren-Honda" will aim to become "number one" in the elite racing world.
The 2015 season will see a reunion of the McLaren-Honda alliance that conquered F1 from 1988 to 1991 with Ayrton Senna and Alain Prost at the wheel.
The tyre manufacturer said the new range combines elements from the 2012 and 2013 tyres to have both durability and performance.
Red Bull clearly believe that Pirelli have gone too far in their efforts to enliven predictable racing with more stops. On Sunday, most teams made four stops per car.
Force India (32) now lead McLaren (29) by three points in fifth place of the constructors standings.
Alonso's win bucked a trend at the Catalan circuit where 18 of the previous 22 events were won the driver who started from pole position.
Rosberg clocked a dazzling best lap time of one minute and 20.718 seconds to outpace his nearest rival and Mercedes team-mate Lewis Hamilton by two-tenths of a second.
Di Resta clocked 1:22.233 to finish last in Q3 while Sutil came up with a timing of 1:22.346 in Q2.
The 27-year-old German clocked a dazzling best lap time of 1min 20.718sec to outpace his nearest rival and Mercedes team-mate Lewis Hamilton by two-tenths of a second.