Narain Karthikeyan [Images] completed 33 laps during the course of the first and second practice of the Brazilian Grand Prix, the 17th round of the Formula One World Championship at the Interlagos circuit in Sao Paulo.

Karthikeyan, driving the EJ15B/01, viewed his practice rounds on Friday in dusty and dry conditions as a "good start" to the weekend.

"Thirty-three laps is quite a good way to start the weekend and I would call this day a positive day," said the Indian.

Karthikeyan completed 14 laps to finish 19th in the first free practice with a timing of 1:16.230 while in the second he completed 19 laps to finish 24th (1:15.187) and last.

He said the track was dusty in the morning and was lacking in grip.

"As usual, it improved a little bit in the afternoon but it cannot show in my timings.

"In the afternoon practice session, I got caught in traffic with Pizzonia in front of me on my flying lap. So my last sector was a bit slow and the time was out of my control," he said.

His Jordan teammate Tiago Monteiro completed 37 laps.

Karthikeyan said although the team had already decided on the tyres to be used in the race on Sunday, it would be discussed further with their engineers.

"We have worked on the tyre choice. I am almost decided, although we will discuss it more thoroughly with the engineers in our meetings. The set-up will need to allow for the bumpy surface. There were not too many vibrations", Karthikeyan said.

"But I am happy with the handling required for the Interlagos track. We need to ride well over the bumps."

However, he conceded that in the end everything would boil down to the weather.

"At the end, the weather will be the key. We do not know what we can expect this year in Brazil [Images], if the weather will be warm, cool or wet.

Meanwhile, with only three races to go, including this race, the battle for the Formula One world drivers and the constructors championship could be settled here.

Renault's Fernando Alonso [Images] with 111 points has a 25-point lead over McLaren's Kimi Raikkonen [Images].

Six points are all Renault's 24-year-old Spaniard needs now to clinch the title, regardless of what Raikkonen does.

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