Renault’s Fernando Alonso surprised many when he set the fastest time in Valencia on Wednesday, but the team’s engineering director Pat Symonds is still unhappy about the R23’s lack of grunt.

Renault’s Fernando Alonso surprised many when he set the fastest time in Valencia on Wednesday, but the team’s engineering director Pat Symonds is still unhappy about the R23’s lack of grunt.

The Spaniard set a fastest time of 1:10.8, in a car that is still waiting for its definitive aerodynamic package.

“We have made good progress since we started working with the hybrid car (on January 23),” Alonso said. “Our previous quickest time at Valencia was 1:11.7. That just goes to show how much we have achieved over the winter.

“I'm expecting that we will make another step forward when we run with the new bodywork. Already, the car is more stable, and has more grip. I have confidence in the car when I'm driving, and that's one of the most important things for a driver,” he added.

However, Renault's executive director of engineering, Pat Symonds, told that he is concerned about the team's engine ahead of the first race at Melbourne on March 9.

After completing a session for Renault at Valencia earlier this week, test driver Allan McNish said of the updated engine: "The car is good, we just need more power."

Last year's Renault engine – a wide-angle V10 powerplant - failed to match the power of its rivals. It was thought to be producing almost 75 kW less than BMW’s engine, which is considered the benchmark F1 powerplant in terms of sheer power.

"We have experienced a few small worries on the engine side, but we are confident that the team will be able to solve them before Melbourne," said Symonds, who went on to say he was pleased with the new R23 chassis' performance.

"From an overall point of view, we are very happy with the R23," he said. "On the mechanical side, the step forward has exceeded our initial expectations and we still haven't really pushed in terms of performance. The car will be fitted with its definitive aero package next week, and we should make another step then."

Valencia test session times, Wednesday 12 February

1 F Alonso - Renault R23 - 1:11,300 - 34 laps

2 R Barrichello - Ferrari F2002 - 1:11,377 - 92 laps

3 R Schumacher - BMW-Williams FW25 - 1:11,478 - 45 laps

4 G Fisichella - Jordan-Ford EJ13 - 1:12,002 - 56 laps

5 M Webber - Jaguar R4 - 1:12,444 - 33 laps

6 J Button - BAR-Honda 005 - 1:12,563 - 58 laps

7 M Gene - BMW-Williams FW24 - 1:12,810 - 61 laps

8 J.P. Montoya - BMW-Williams FW25 - 1:12,988 - 96 laps