Timo Glock has suggested that, with the exception of the Brawn GP team, no other can be certain of where it stands in Formula One's form list from race to race.

Speaking on the eve of the Bahrain Grand Prix, at a circuit where Ferrari, BMW Sauber and Toyota tested during the winter, the German admitted that it was hard to predict how each team would fare before a race weekend got underway, with form appearing to be determined as much by track layout and conditions as by the potential of the cars.

"For me, it looks like it's a bit track dependent," he said when asked how he felt Toyota stacked up against 2009 race winners Brawn and Red Bull, "We were quite strong in Malaysia and, in Shanghai, we struggled a bit so, for me, maybe the gap to Brawn is slightly bigger, slightly lower depending on the track. But they looked quite strong in Q3 in China as well - with a lot of fuel on board. After Brawn, I think it's always track dependent who is quicker."

Like many of his rivals, Glock admitted to having been surprised by the performance of the two Red Bull machines in China, where Sebastian Vettel and Mark Webber overcame the Brawn supremacy to claim 1-3 on the grid and finish 1-2 in the race.

"They were quite strong already at the tests and, at the end, they developed from race to race - the race in Australia showed already the pace," he reflected, "Sebastian was in P2 in the race and, in Malaysia as well, they were quick, so it is not a big surprise. I think they made a little step, or they were maybe just a little bit better sorted out, [in China]. The temperatures in Shanghai were quite cold compared to the other races and maybe that is part of the difference but, for me, they looked strong in testing."

Asked whether he felt that testing in Bahrain pre-season would give Toyota an edge this weekend, Glock admitted that conditions had changed in the space of a couple of months, but added that it would be important to try and continue his 100 per cent scoring start to the season before the schedule heads for Spain, where all teams are likely to introduce updates to their cars, potentially altering the balance of power.

"We have to wait and see," he said of the potential for success in Bahrain, "The test we did here was quite different to the conditions we have now, as it is much warmer. This will be one point for tomorrow to see where the car is. We are still missing a little bit with the car we had in the winter tests.

"They were pretty consistent - every time we went out in the car, it didn't really have any problems with the set-up and, now, over a race weekend, when we start on a Friday on a green track, it is a bit tricky with the car and we have to try and find a way to get it more consistent over the weekend and have a stronger start. A good qualifying is important to start more in the top ten, top five, to be able to fight for the podium.

"I didn't really expect the points [in China], but we had a strong race in Melbourne and Malaysia with the right tyre choice. We did everything right in the race and, again in Shanghai in wet conditions, we had quite a good pace. I think I was twice behind the whole field and to come into the points again was good - we have to be satisfied with it."

The German confirmed that there were no current plans for the Toyota team to run with KERS in an effort to keep himself and team-mate Jarno Trulli ahead of the pack - not necessarily a guarantee anyway, given the recent decisions by Ferrari and Renault to suspend KERS usage - but admitted that it was important to keep up the development of the TF109, even though the ban on testing made it harder.

"We are not planning to use KERS, but we have to be careful in terms of development," he confirmed, "We have to be stronger now even than in the winter time to keep that advantage against the other teams. Everybody will come up with a new aero package in Barcelona and we have to fight for that position where we are at the moment. For me, Red Bull made quite a big step in China - they were really quick and we have to fight so that we can stay in that position where we are at the moment.

"We will have to wait for Barcelona to test the new parts on Friday in free practice, but it's not an easy situation because, when you get new parts for the race weekend and you have to try them while the track is evolving, it's quite tricky to sort that out. But, at the end, we all have to deal with it, it's all the same."