Jenson Button says 2014 McLaren F1 car does not have 2013 'issues'

The 2009 world champion topped the second day of running at Jerez in the MP4-29, despite the fact the car did not run at all on day one.

Given that he missed out on the opening day, Button will continue in the car tomorrow for an extra half-day before handing over to rookie team-mate Kevin Magnussen for the rest of the test.

McLaren also enjoyed a positive first day with its car in testing last year, but Button believes things are different this time.

"Our first day last year was quick, but our car had its flaws and we could see that on day one," he said.

"We had issues that were not going to be easy to solve and at this moment in time we definitely don't have those.

"The basic car is good and it works, no scary things with it."

Minor problems prevented longer runs, but Button believes he can already see how the MP4-29 can be improved.

"The good thing is we were able to solve the issues pretty quickly and get out there and put some laps in," he added.

"Everything's new with this car so I am amazed we were able to go round and do as many laps as we did today.

"There's no horrible issues with the car itself, no big issues with the power unit in terms of how it delivers. The basic car is where we want it to be.

"How much we're going to add to this car, aerodynamically and in terms of the engine, is massive so having a good base is important.

"The great thing is I know exactly what they are and how we can improve the car.

"There's a lot we can do overnight, which is exciting, and I'm looking forward to getting back in."