Renault's Nico Hulkenberg concluded the team's first day of pre-season with the fourth fastest time and some good impressions to go with it.
The German driver raked in 73 laps in the first half of the session - the most laps of anyone in the morning - before team mate Carlos Sainz took over testing duties in the afternoon.
It was a productive day for team and driver with both gaining significant knowledge of Renault's new R.S.18.
"First impressions are positive to be honest," Hulkenberg said.
"Especially if you compare to 12 months ago how the first morning went and how it went today, it’s a huge difference.
"We’ve made a lot of progress. The car ran really well, was reliable and we really got through every single detail on the program which is really unusual for the first day! I’ve not experience that so many times.
"So it was a good job and a credit to our guys that prepared really well."
Like his colleagues, Hulkenberg noted the big surface change at the Circuit de Catalunya, which offers drivers much mopre grip to contend with.
"In terms of feel of the car, like I said I felt quite good straight away. The big thing though is the resurfacing of the track here has quite a big impact.
"It’s much smoother and quite a high grip surface I think so that changed the picture of the Barcelona track in general a lot by itself.
"Therefore it’s kind of harder to compare back to last year, but I think the starting point was definitely OK today."