Mercedes drivers Nico Rosberg and Lewis Hamilton say they focused on long run pace during practice for the Malaysian Grand Prix.
Rosberg was fifth and seventh fastest in the two sessions.
"We worked a lot on our long run pace today, rather than being quick over one lap. As we saw in Melbourne, tyre management will be the key to success, so that's our focus for the practice sessions," said the German.
"The conditions were tough out there and the heat is unbelievable. Generally we learnt a lot today but we still have some homework to do tonight and tomorrow."
Team-mate Hamilton was ninth fastest in both sessions.
"We made some positive steps with the set-up over the two sessions today. I had a good long run in the dry which has given us a lot of information to look at tonight," he said.
"We didn't learn too much in the wet this afternoon however as the conditions were quite mixed when I went out. We focused mainly on longer runs today so I haven't done a quick lap yet on either set of tyres; that will come tomorrow. I'm happy with the direction that we're going and let's see what the weekend brings."