Romain Grosjean set the third fastest time on the opening day of the Belgian Grand Prix weekend, with Kimi Raikkonen sixth.

Rain affected proceedings in the morning session - during which the team ran evaluations with the Device - whilst dry conditions in the afternoon saw both cars run with slimline bodywork in non-Device configuration.

Both cars ran the Device in the morning using Pirelli's intermediate (green) tyres. Both cars ran in non-Device configuration with slimline bodywork in the afternoon. Kimi tried a new front wing in the afternoon.

Weather factors meant that there was insufficient track time to evaluate the Device in suitable conditions. The car demonstrated good pace during the afternoon in all configurations utilised.

Kimi Raikkonen: "I feel fine here today and the car was okay. It could have been a bit better, but it wasn't a disaster either so for sure we can improve a bit more for tomorrow. The weather wasn't great this morning and it's certainly better for us when it's dry. We had a little problem with the front wheel in the first session which meant we didn't run as much as we wanted to. The afternoon was pretty normal. For sure it looks like it will be a difficult weekend to beat Red Bull but that's what we must try to do if we want to catch them in the Championship."

Romain Grosjean: "It has been a busy day. We had planned to focus on evaluating our Device this morning, but with the changing atmospheric conditions we weren't able to 100% complete all the tests so with more rain forecast we decided to take it off for the afternoon to concentrate on a more normal programme with long runs. It wasn't that easy as we found it quite hard to make the tyres work the way we would like them to which meant that in the car the feeling might not have been so good, but timing-wise it was actually okay. The car felt pretty good and we'll work on this baseline to continue to improve. We'll wait to see what the weather will have in store for us."

Alan Permane, Trackside Operations Director: "Unfortunately the wet conditions this morning meant we weren't able to get as much work done as we wanted on our Device so we elected to revert to a known set-up for the afternoon, with everything going to plan. Neither driver was entirely on top of their car, but given the conditions today I don't expect any team was after the mixed weather in the morning. We concentrated a little on set-up and more on tyre evaluation ready for the rest of the weekend. From the data we've seen so far we look reasonably strong on pace and tyre performance, so we're looking forward to the rest of the weekend."

Check out our Friday gallery, here.