MONTREAL, Canada, June 6, 2008 (AFP) - Jarno Trulli admits that he is in the dark as to what kind of results his Toyota team can expect from Sunday's Canadian Grand Prix.

Trulli and his German teammate Timo Glock completed a good number of laps in the two Friday practice sessions at Circuit Gilles Villeneuve, but both drivers made a number of mistakes as they battled to find a suitable setup.

According to the experienced Italian, a combination of the poor grip on the rain-affected circuit and a lack of testing, means that Toyota are behind their rivals in terms of preparation for Sunday's race.

After a difficult morning session, Trulli did sneak into the top ten after lunch, but he did not exactly sound confident when interviewed back in the paddock.

"Our day of testing at Paul Ricard in preparation for this race was washed out so we had a lot to learn from today's practice sessions," he said. "This was a difficult day because the track was green and there was very low grip."

"That meant I was fighting a lot to control the car and to get the most out of the tyres. In general we have quite a lot of work to do to improve the balance before qualifying. It's hard to say how we can get on this weekend."

"The role of the tyres will be important because we had graining last year which had a big impact on the performance."

"We've had some difficult races lately so we could do with a return to form here."

Glock was 13th fastest in the morning and 15th in an afternoon session that was cut short after he clipped a wall and was left stranded on the track. However, the German, in his first full Formula One season, has fond memories of racing in Montreal and believes he can continue that form over this the weekend.

He said: "The first practice session went okay and we were able to carry out useful work in the changing conditions."

"But in the second practice I just could not find a balance and the car was really difficult to drive. I put a wheel into the wall with half an hour to go and that was it for the day."

"Still, my races here in Montreal have gone well for me so far. I scored points here on my F1 debut in 2004 and I came second here in Champ Cars."

"So I have good memories from this track and I remain hopeful we can come away from this weekend with a strong performance."

Championship leader Lewis Hamilton set the fastest time of the day, the British McLaren driver just edging out BMW Sauber's Robert Kubica.