Fernando Alonso has declared the F138 as being similar to its predecessor after getting his first taste of action in the 2013 model on Tuesday.
Felipe Massa enjoyed all the action at the first test in Jerez, but it was Alonso's turn to get behind the wheel at Barcelona.
The Spaniard notched up the third fastest time of the day with a 1:22.952 and by completing 102 laps was the most active driver.
Reflecting on the day's running, the former World Champion didn't get carried away with his praise.
"The feeling with the car was okay, as expected more or less," he said.
"It's a similar continuation of the Brazil car, let's say, so it's more or less the same feeling. I have the same seat, I have the same pedals, I have the same everything so when you jump in the car more or less the performance should be the same as Brazil.
"It's nothing really surprising you when driving, so this is at least something good, not like last year when we drove for the first time we were a little bit surprised on the bad side. We have a lot of work to do; a lot of work to do in the next days for the tyres, for the aerodynamics, for some new components and experimental things that we have in the car. We need to keep doing a lot of mileage; in Jerez we had some mechanical problems - especially with Pedro we lost one morning - so we need to put some good laps in this test to prove the car is strong enough to race."
One area where Alonso was a lot more vocal was on the issue of the Pirelli tyres.
"Obviously we concentrate on our job - we don't know what the others are doing - but it's maybe not the best option to test in the winter when you have a tyre that will do one lap because we have so much stuff to test and so many new things that we have to have clear and good information on those parts," he asserted.
"You only have one lap to understand what you put on the car because then you are two, four, six seconds of the pace. But it's the same for everybody so we need to understand these new tyres better than the others if we can and try to make them last as much as possible."