Jenson Button: 100 F1 test laps for McLaren-Honda felt like 1000

The Woking-based F1 squad has suffered a spate of engine problems since testing began at Jerez last month, while the team has also had to rest returnee driver Fernando Alonso following the Spaniard's crash at Barcelona last Sunday.

A hydraulic problem on the Honda engine ruined McLaren's first day of this week's final pre-season test, but on Friday Button managed to clock the team's highest lap tally so far.

The 2009 world champion completed 101 laps before a minor electrical problem stranded the car at the exit of Turn 7 with only a few minutes of the session left to run.

"It felt nice to do 101 laps, reliability has been great today - a really, really big step forward and big effort from everyone," Button said.

"If you look at the timing screens, we are nowhere near quick enough, but there is a lot of progress and a lot we can improve on for the next couple of days.

"For a lot of teams 100 laps isn't anything, but for us it is like 1000 laps, because there is so much for us to learn about this package."

'LONG WAY TO GO'

Button said McLaren-Honda would need to use the final two days of pre-season testing to improve engine performance and set up the MP4-30.

"We know there is more we can achieve with the power unit - I think we have made good progress but there is still a long way to go," he added.

"I have not done a massive amount of set-up work, [because there are] so many back-to-backs you do with aero parts, with ride-heights and front wings that will gain you a big chunk of time if you get it right for the first race, whereas set-up work will gain a few tenths.

"A lot of work is needed on set-up to hone car to the way I drive, which is why I need a good day on Sunday.

"The feeling is reasonably good, but work in progress - we are definitely not where we need to be."

Reserve driver Kevin Magnussen will take over from Button on Saturday, while Alonso recuperates following his accident last week.