Renault found three tenths on rivals
The improvements allowed Fernando Alonso to run closer to the front and even qualify on the front row, although he was running two laps of fuel lighter than the cars around him.
"I can say that at Barcelona we probably moved three tenths of a second closer," Symonds said. "Whether that will be the same in Monaco and Turkey I'm not sure yet, but the evidence at the moment indicates for that kind of improvement still."
"We're going the right way and lots of things we tried worked," he added, "We just have to keep working at it. The gap is still pretty big, especially to Ferrari so we have a lot to do but we're pleased with the direction."
"We improved 19 separate areas of the car last weekend and we have got to keep doing more of that," he concluded.