Lewis clocked 750km on his final day at the wheel of the W08, posting a best time of 1:38.551s on the new for 2018 HyperSoft Pirelli rubber.
"I'm not really the biggest fan of testing, but it's been a positive first day of running with these new tyres," said Lewis.
"We managed to complete plenty of laps and collected lots of data and feedback to ensure we head in the right direction over the winter. We've got a good early understanding of these 2018 Pirelli tyres.
"On early impression, the new HyperSoft is the best tyre that Pirelli have produced since returning to F1. I found that the other compounds are still a bit too hard for my liking but we're moving in the right direction.
"It's a nice way to wrap up the season, with one last day in the W08. I'm definitely ready to take a break now, though!"