Jenson Button exclusive: Fernando Alonso pairing perfect for McLaren

Jenson Button says his partnership with Fernando Alonso is "perfect" for McLaren as the team plots a way back to the summit of F1.

After two successful days in Barcelona when 2016 pre-season testing began last week, the team were restricted to just a handful of laps on Wednesday and Thursday due to unreliability.

But McLaren - along with engine providers Honda and partners ExxonMobil - are delivering a host of upgrades for the MP4-31 for the final test this week when Alonso and Button will learn how much lap time the team have gained over the winter.

"This week's test is the really important one," Button, who will drive on Wednesday and Friday, told Sky Sports in an exclusive interview.

"We'll now see where our improvements are. The guys have been working flat-out on the car over the winter and it's been a good winter but now we have to see whether we get the gains we expect.

"This week I'll get a much better read into where the car stands."

With team boss Eric Boullier predicting "massive gains" in 2016, Alonso was an encouraging third fastest on Day One of the second test. It's understood McLaren are trialling a new type of fuel in the Spaniard's car as well as the engine Honda expect to use at the start of the new season.

"It's massive for us to have a partner like Exxon and this should be another chunk of time to look forward to," Button added. According to Boullier, the new Esso fuel could be worth a 'double digit' boost in horsepower.

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While both Alonso and Button impressed in 2015, it was for their stoicism in adversity as much as their efforts on track. Only Ferrari currently also boast an all-champion driver line-up and Button is convinced that the experience he and Alonso bring to McLaren will be vital in their quest to return to the front of the grid.

"This is the perfect partnership for this team because we have our heads screwed on," Button explained. "In terms of development it really helps. 

"I think he's regarded as one of the best drivers to have ever driven a Formula 1 car. We've both won world championships and having been in that position you can get through the pain of last year. I think we've moved this team forward."

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Play the video at the top of the page to hear Button's thoughts on 2016, F1's plans for the future, and the importance of not over sleeping...