New Red Bull ‘not slow’ – Webber
The Australian, back at the wheel of the RB5 on Friday following his return from a broken leg earlier this week at Jerez, said the car's maiden test has gone "pretty well".
But amid expert suggestions it might be a match for the McLaren, Ferrari and BMW this year, 32-year-old Webber is keeping his enthusiasm at bay.
"First impressions of the car are pretty good," he said in his latest BBC column.
"We have work to do. We're not the quickest yet, but we're certainly not that slow," added Webber. "We're pretty encouraged, but it would be suicide to predict anything now."
The Adrian Newey-penned car, powered by a newly improved Renault engine, has at Jerez looked a near-match for the McLaren MP4-24, which has been fitted with a 2008-spec wing.
Webber says it is "obvious" that the McLaren "is very quick".
He was a half-second off Heikki Kovalainen's pace on Wednesday after more than a full race distance, and said he woke up the next day "feeling great" despite giving his fragile leg its toughest work-out since last November.
"We will probably tackle the rest of the winter testing as if I'm totally normal, which is very encouraging," he explained.
"I discovered that I can drive at 100 per cent, which is pretty amazing, really, when you think about what I've gone through," said Webber.