A major rule shake-up in saw the 2.4 litre naturally aspirated V8 engines replaced by 1.6 litre turbocharged hybrid power units. This prompted Honda to return to the sport in 2015 as the championship's fourth engine manufacturer. Mercedes emerged as the dominant force after the rule shake-up, with Lewis Hamilton winning the championship closely followed by his main rival and teammate, Nico Rosberg, with the team winning 16 out of the 19 races that season (all other victories coming from Daniel Ricciardo of Red Bull). 2014 also saw a financial crisis which resulted in the backmarker Marussia and Caterham teams being put into administration, alongside the uncertain futures of Force India and Sauber. Marussia returned under the Manor name in , a season in which Ferrari were the only challenger to Mercedes, with Vettel taking victory in the three Grands Prix Mercedes did not win.