Sahara Force India had a positive first day of on-track action at the Autodromo Hermanos Rodriguez.

Nico Hulkenberg: "The main focus on Friday is to complete your programme without issues, and from this perspective we had a good day. Most of the challenges we are facing are the same as last year - the altitude makes a big difference to the feel of the car with a loss of downforce - so we need to adapt to the conditions to find the ideal balance for the car. The rest of the day was quite standard, mostly learning about the tyre compounds, and I feel we did a good job with it. The morning session didn't tell us much: the track was very cold and very dirty, so getting good information was difficult. We were able to assess the tyres in the afternoon and there wasn't any particular surprise. In terms of car balance, we have made a good start but I am not completely happy yet: there is still a good margin for improvement and I hope we can dial our car in to find it overnight."

Sergio Perez: "Racing at home is a very emotional moment, but when I get in the car it's important that I treat this weekend like any other race. The morning went very well and I had a good feeling with the car. I struggled more in the afternoon, but we know where we need to focus and the direction we need to take to improve for tomorrow. The conditions today were not what we anticipated, but the rest of the weekend should be warmer: we will need to set the car up for what we think we are going to find on race day, but I think the data we collected today will allow us to do so."

Robert Fernley, Deputy Team Principal: "It was very cold this morning, meaning the conditions weren't very representative of what we expect for the rest of the weekend. Track temperatures were slightly higher in the afternoon, and we could focus on understanding the two race tyre compounds: medium and soft. We didn't have any interruptions and gathered a lot of good data about how to set the car up on race day. Overall, Nico appears happier with the base balance of the car, whereas there are still a few elements on which to work with Sergio. Our focus now is on preparing the car for qualifying with a view to extracting the most out of it - it's the work we will be doing in the final practice session tomorrow morning."

Check out our Friday gallery from Mexico City, here.