Daniel Ricciardo has suggested that seventh place at Sunday's Spanish Grand Prix was the best he could do with the car.
The Aussie was unable to match the pace of Ferrari or Williams in the chasing pack behind Mercedes, with teammate Daniil Kvyat finishing in 10th place.
However, despite the result, Ricciardo is hopeful of improvement when he races at Monaco later this month.
"I am more satisfied today as we achieved everything we could and seventh was the maximum I could get out of the car," Ricciardo told reporters. "There were some parts of the race that were encouraging but we're still further off than where we want to be, but we'll keep pushing.
"We came here with upgrades this weekend but they didn't give us what we were expecting, so that's something we'll keep working on. We're still a fair bit behind Williams at the moment but I think we have a good chance to close the gap a bit further in Monaco."
Ricciardo finished third in last season's drivers' championship.