Narain Karthikeyan [Images] continued to struggle while his teammate Tiago Monteiro enjoyed a problem-free drive in the new Jordan-Toyota EJB15 in the practice sessions ahead of the Italian Grand Prix in Monza, on Friday.

Karthikeyan suffered a puncture in the first practice session and managed to finish 15th but was relegated to 21st in the second practice at the Monza circuit.

Tiago Monteiro, who got the chance to drive the new car ahead of 28-year-old Indian, was 12th and 20th respectively in the two sessions.

Narain said his team and tyre manufacturers Bridgestone are investigating the incident and said he could not finish as many laps as he expected.

"I am satisfied with my times during the practice session and I am happy the way things went. With 1.24.202, I am pretty close to Tiago Monteiro's performances who finished in 1.23.994 with the brand new car," the Indian Formula One driver said, exuding confidence about the race on Sunday.

"I like the Italian track and its high-speed straights with cars at almost 360 kilometres an hour," he said.

With five races left in the season, the drivers and constructors championship are far from settled.

Renault's Fernando Alonso [Images], with six wins, heads the drivers championship by 24 points from McLaren-Mercedes' Kimi Raikkonen [Images].

McLaren trail Renault by nine points in the constructors standings.

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