Force India newbie Esteban Ocon had a "very enjoyable" first day in the VJM10 and declared the new cars "proper beasts".
Ocon, on his first appearance for Force India, racked up 86 laps and finished P5 after the second day of testing in Barcelona – a decent recovery after suffering an oil leak problem early on.
"A very enjoyable first day in the VJM10," said Ocon.
" It’s very early days, of course, but the initial feelings are positive and we found a good direction for setting up the car.
"The only issue was an oil leak just before lunch, but it didn’t cost us much track time and I’m satisfied with the number of laps we covered. I hope we will make similar progress tomorrow and the day after.
"This was my first experience of the new generation cars and I have to say they are proper beasts: the high-speed corners are very impressive and there are big gains in the low-speed corners so it’s a good step forward.”