David Coulthard is keeping his hopes and expectations in-check ahead of his valedictory outing in Formula 1 in the Brazilian Grand Prix this weekend – revealing he would like to see one more chequered flag before walking away from a sport that, over the past decade-and-a-half, has given him so much.

The experienced Scot will hang up his F1 helmet at the end of 15 seasons of competition in the top flight that have yielded 13 grand prix victories, twelve pole positions, 18 fastest laps and a mammoth 535 points – making him statistically the highest-scoring British driver of all-time, and fourth on the overall list, behind only multiple world champions Michael Schumacher, Alain Prost and Ayrton Senna.

Just eight of those points have come during a largely disappointing final campaign with Red Bull Racing this year, however – courtesy of seventh place in the inaugural night-time event in Singapore and an unexpected but no-less deserved rostrum finish in Montreal – and the 37-year-old, tipped to join the BBC's F1 commentary team in 2009, is aware that he may now have scored for the last time.

“I guess I should be emotional,” reflected the man from Twynholm, “but I think it will be more on Sunday when I step out of the car for the last time, hopefully after the chequered flag, and realise that this part of my life has come to an end.

“It is difficult for anyone to imagine what that might be like. I am not stopping because I don't love driving grand prix cars or I don't love racing, but I recognise that my journey has reached its natural conclusion, so when I walk out of the paddock on Sunday that will be it.”

Coulthard ended the opening day's practice around the Autodromo Carlos Pace at Interlagos twelfth-quickest – six places albeit just over two tenths of a second adrift of RBR team-mate Mark Webber – and he acknowledged the unpredictable conditions had rendered things somewhat…unpredictable.

“There were changeable conditions out there,” he mused. “It was spitting with rain in the second session, so we took the decision to run a fresh set of tyres early on, just in case it rained towards the end. We haven't achieved the ultimate lap time, but I think we made progress during the day to stabilise the car.”

“We had a pretty productive day,” added Webber. “I was happy with the car quite early on in the session as we got the balance right, which is always a good start. Getting on top of the tyres is not easy and we had quite changeable conditions, but overall that was a good start to the weekend.”