Alonso finished as championship runner-up in three of his five seasons with Ferrari, but now lies 16th in the table with just 11 points to his credit, his last Grand Prix podium a distant 16 months ago in Hungary. But despite the slump, the Spaniard insists his move was correct.
"Well, tough year - obviously difficult and struggling with the pace all year and the reliability, so definitely a difficult season for us," Alonso said in Abu Dhabi on Thursday when asked to sum up his 2015 campaign. "But personally I think it was necessary.
"It was a step forward in my career after the two championships, after five fantastic seasons fighting for the world championship but arriving second, so I needed some new motivation, some new project that I could trust and I could believe is the only way to become champion again.
"After one difficult season, as I said, I learn so much. I enjoy working with McLaren, with Honda, with all the Japanese discipline and Japanese culture into the team. I still remain very positive.
"I'm very, very happy and looking forward to next year being a little bit easier than this one that, as I said, has been difficult in terms of results."
Alonso admitted, however, that McLaren's prospects for 2016 remain uncertain, especially concerning whether he will be able to fight for the championship.
"At the moment there's a question mark, I guess, where McLaren-Honda can be next year," he commented. "There are a lot of expectations in the team.
"I think we worked really all season, being united in some difficult moments and always moving forward, so I think for 2016 the main goal for the team is to come back to where we belong, we think, and being competitive, fighting for the top positions. I don't know if that means fighting for the championship, I don't know if that means fighting for victories or just being on the podium sometimes, that's always difficult to know in a very complex sport like Formula One.
"There are definitely some big challenges ahead in this winter and I see all the things that the team has done in the last couple of months and these seem very logical, very positive and I'm confident that it's going to be a completely different season next year and I'm happy with the progress."
Alonso goes into this weekend’s 2015 Formula 1 Etihad Airways Abu Dhabi Grand Prix trailing McLaren partner Jenson Button by five points in the standings. He has never before been out-scored by a team mate over the course of a season.