 The RA615H was widely criticised by the wider Formula One community , with the team 's struggles becoming a recurring theme throughout the 2015 season . This criticism was particularly directed at Honda 's Project Manager Yasuhisa Arai and the rigidly compartmentalised structure between the two companies that saw Honda develop the engine independently of and with minimal input from McLaren , and their failure to recruit any engineers from rival engine manufacturers Mercedes , Ferrari and Renault , even after Arai 's acknowledgement that Honda had underestimated the demands of the sport and the technology required to compete . Responding to the criticism , Arai claimed that the " size zero " approach demanded by McLaren — attempting to create a more compact design to fit the tight packaging of the MP4 @-@ 30 chassis — had compromised the overall design of the engine and limited the ability to develop it over the course of the season . Fernando Alonso defended the move , suggesting that Honda 's independent development programme would make it difficult for other manufacturers to copy the RA615H 's design . McLaren CEO Ron Dennis took a broader view , attributing the team 's difficult season to a range of factors — including chassis development and staff morale — rather than the engine performance alone . 
