Heikki Kovalainen admitted it was hard to see how much of an impact Caterham's latest update will have after a rain-affected start to the British Grand Prix weekend.

The team was hopeful that changes introduced onto the CTR-01 would allow Kovalainen and Vitaly Petrov to move closer to the established teams, although the poor weather that affected Friday's running limited the team's time on track to evaluate the changes made.

"I think that's the wettest day we've had in F1 for quite a while and that cut short the amount of running we could do today," Kovalainen, who was seventh quickest in FP2, said. "It was pretty treacherous out there in both sessions, more so in the afternoon when I was getting wheelspin at the end of the straight and when it's like that it's not worth risking the car, particularly when we have quite a lot of new parts on it that we need to take a look at as much as we can this weekend.

"As it was so wet I can't really say how much of an improvement we've made here, but this morning the car felt pretty well balanced as soon as I started to push a bit, so if it's raining like this on Sunday at least we know we have a decent setup to race with."

Technical director Mark Smith admitted it was a shame to see the two practice sessions so badly affected by the weather, especially with a bumper crowd having made its way to the circuit to watch proceedings.

"It is obviously a shame for the fans and the teams alike that we had such limited running today, but the conditions were so bad in both sessions that the risk of accidents was too high for us to run any more than we did today," he said. "Despite that we were able to complete a number of useful tests this morning, running comparisons between the new upgrades we have brought here with the package we raced in Valencia.

"That gives us a relatively decent amount of data to go through to understand what sort of gains we have made, but the initial numbers are encouraging."