Ocon covered 86 laps once the team took care of an engine oil leak which kicked off the day, running through the team's aero programme which had been started by Sergio Perez yesterday.
"A very enjoyable first day in the VJM10," said the young Frenchman.
" 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."
Ocon admitted to be impressed by the new generation cars.
"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.”