The 2016 F1 season has well and truly begun with the first pre-season test underway at the Circuit de Catalunya in Barcelona. All 11 teams have unveiled their cars for the upcoming season, something that is sure to evolve as the campaign progresses.

The number of changes on the front end of the cars is minimal with just Ferrari changing their approach from last season and opting for a much shorter and stubbier nose, but there are a number of changes in the opposite end, with teams reworking their power units to improve the packaging at the back.

The first day of test saw the Ferrari of Sebastian Vettel take the honours for the quickest time, but it was reigning world champion Lewis Hamilton, who impressed the most as the Mercedes team completed 156 laps, which is over two full race distances, underlining the reliability of the Silver Arrows team. The overall consensus among all drivers is that the cars are a sure step- up from the last season.

Nico Rosberg will take over from the Briton on day two of the test, while Vettel will retain his seat.

Here is what the drivers from Mercedes, Ferrari, Williams and McLaren-Honda had to say following their first run in the 2016 challengers, as quoted on ESPN F1.

Lewis Hamilton – Mercedes

"It's good to be back. It really had felt like a while - but now it feels like home already. I'm glad to see I can still drive! The car has been great so far. It's very similar to last year's - which is a good thing, as it gives us a great foundation to work from.

The key is to get as much mileage as possible in the short time we now have for testing and we've made a fantastic start. The team has done an incredible job to get the car running the way it has - completing so many laps with no real problems. That's seriously impressive on the first day, so fingers crossed it continues."

Sebastian Vettel - Ferrari

"We had the first proper day of testing today, from which we got a first feeling from the car and the first impression is good, I think the new car is a step forward. I felt confident enough, but we know there is still a lot of work in front of us. For sure there have been changes inside and outside the car.

Laps times today are not important at all: they will be in a month's time at the Australian Grand Prix! It was good to have some laps, I would have liked to have some more but it is natural that when you have something new and things you want to check you are more conscious, so you stop to have a look at them, and unfortunately this all takes time."

Valtteri Bottas - Williams

"It's always very nice to be back in the car and it's nice to feel that we have made improvements, but it is way too early to say anything more than that. We were focussing on different kinds of tests today with the chassis, and some aerodynamic tests so mainly longer runs.

We had a few problems but that's testing, and hopefully we will have a clean run tomorrow. First impressions of the new car are good and I think we have fixed many issues from last year. However, like I said before, it's just too early to say where we are against the others."

Jenson Button – McLaren-Honda

"I've missed Formula One massively over the last few months - it seems like the longest break I've ever had in my career - so it's great to be back, to be in the car, and get some laps under my belt. Today has been all about system checks and trying new things - there are lots of differences with this car, and with the engine. The stand-out thing that's been very positive today is the deployment: it's been very consistent throughout the day, we had no issues, and it was quite a bit better on long runs than last year. This is good, because it allows us to see other weaknesses in the car that we still need to improve."