Today was a challenging but ultimately productive day on track for the first outing of the second and final pre-season test.

Stoffel took to the track shortly after 09:00, and the team worked progressively through its test programme, which featured more aero correlation, tyre testing and balance and handling evaluations.

Shortly after midday, Honda detected an electrical anomaly in the power unit, and, in order to investigate further, elected to undertake a complete PU change.

The team worked extremely efficiently to get the car back up and running – the engine change taking less than four hours – allowing Stoffel to return to the track shortly before 16:00.

In the afternoon session, the team completed more useful mileage, conducting aero tests and simulation of the type of running expected in Melbourne. Stoffel completed 80 laps by the time the chequered flag fell at 18:00.

Stoffel Vandoorne: "Today was certainly a day of mixed fortunes for us. Having another issue with the power unit has been of course frustrating for everybody, but the team dealt with it extremely well and I'm pleased we managed to get back out on track this afternoon.

"Losing track time is obviously not ideal, but when we were on track we actually managed to get a large chunk of our test programme done, and we learned a lot more about the car today. We tried a lot of different things with the aero, balance and set-up, and also went through a lot of procedures and car behaviours that I will need to prepare in time for Australia.

"It hasn't been the ideal way to start the second test, but considering the issue we've had, we've still managed to complete a good number of laps, and we go into tomorrow hoping for more track time and more solid data that we can take forward to Melbourne."

Eric Boullier: "While losing out on track time definitely makes things challenging, I'm not too concerned yet. The aim for us is to generate as much data as we can. Of course, less mileage means less time to understand and develop the car and validate parts, but since everything in this current era of Formula 1 is based on simulation, the most important thing for us is to correlate the data with the simulation numbers back at the factory. We would always like to do more, but from what we've seen so far, we're pleased that we generally have positive correlation in line with our predictions.

"Reliability is key to allowing us to develop further and get closer to the limit, and we're working closely with Honda who are investigating the power unit issues and working hard to progress through them in order to improve our reliability. They are our partners, we support them and we have to trust that they can address these issues in time for Australia.

"Overall, while on the face of things, another reliability issue is naturally frustrating, we still managed to get a lot of laps on the board. I salute our guys in the garage who managed to conduct a complete PU change in under four hours, which is highly commendable, and it meant we were able to complete some useful areas of our test programme.

"We're hopeful that some of the power unit issues we've faced will be addressed in the second specification of engine that we plan to run later this week, so there's definitely more to come from us and we'll keep going."

Yusuke Hasegawa: "In the morning session, Stoffel started today's extremely busy testing programme. After completing 34 laps, we detected an electrical issue in our power unit, which is the same specification as last week. In the interest of maximising track time, we opted to replace it and investigate the issue further once the PU is out of the car. We were able to restart our session in the afternoon, and Stoffel finished 80 laps in total today.

"It's been another tough day, but once again the team has worked incredibly hard to get the car back out on track, and we still have three more days to gather more important data in our preparations for the start of the season."

Check out our Tuesday gallery from Barcelona, here.