Ferrari team chief Stefano Domenicali was encouraged, but not satisfied, by the improvement which saw Fernando Alonso finish second in Sunday's Belgian Grand Prix.
The Italian boss said he was pleased to see progress -as the two-time champion Spaniard turned ninth on the grid into a podium finish - but wanted more pace ahead of next week's Italian Grand Prix at Monza.
"I think it was important not only for Fernando, who deserved a very good car, but also for the team," he said.
"They are working very hard to make sure that we are able to fight until the end in the championship. We had a very bad July for many reasons and I am very pleased to see we are back on track.
"But it is not enough. If we want to make sure that we arrive at the end, then we need another step with regards to the performance of the car.
"At least that is what I am telling my people. For us it is important to keep improving the car. We see Red Bull have for sure improved, so we need to improve the car more than them and be there if there is an opportunity, because they may have a problem."