Sebastian Vettel believes Ferrari could in a better position to challenge Mercedes next season after making progress over the course of 2015.
Vettel is the only driver to have mounted any sustained threat to world champion Lewis Hamilton and Nico Rosberg, claiming race wins in Malaysia, Hungary and Singapore.
The German was also the Mercedes duo's closest challenger in qualifying for the Brazilian Grand Prix on Saturday, but was still almost half a second off the time of second-placed Hamilton.
However, with only one race to come after Interlagos, Vettel is confident Ferrari can bridge the gap during the off-season.
"Well, I think what you do in qualifying is you try to go as fast as possible, so it's pace in general that we are still lacking - but, you know, the season is coming to an end slowly," he said.
"I think generally, looking at the last couple of months, we managed to get closer. Of course from race to race, from track to track the gap can vary a bit, but overall I think things are heading in the right direction.
"Also, in-season, it is possible to bring updates - everyone is - but it's difficult to make really, really big changes to the car, so I think next year should give everyone the opportunity to refresh and renew a couple of things and hopefully we can be in a stronger position."