Brawn: Forward exhausts not essential

Renault caused a stir at the opening Formula 1 test in Valencia when its new R31 featured sidepod exhausts - which exit at the front of the car to blow gases along the under-body.

A number of rival teams are believed to be evaluating a similar concept - including Mercedes GP, Red Bull Racing and McLaren - although none have used it yet.

Speaking in Valencia, Brawn did not think that Renault-type exhausts would become a must-have item in 2011 - although acknowledged that using gases to improve under-car downforce was vital.

When asked if Mercedes GP would need to adopt a Renault-type design, Brawn said: "I don't think so. I think you'll see probably a number of teams with different solutions before you get to Bahrain.

"I saw Ferrari, and they had some different options. I think there are a few different solutions you can do to get the benefit from the exhaust energy. So I think you'll see a lot of different solutions before Bahrain."

Brawn said he has not seen anything on the new cars of main rivals Red Bull Racing and Ferrari that worried him too much.

"I haven't seen them properly to be honest, but I see nothing dramatic on them," he explained. "I suspect at all the top teams, you're going to see a very different car at Bahrain, because of the period between now and Bahrain.

"I think most of the teams are going to come up with their first major update before we get to Bahrain. I mean certainly that is the case with us.

"What we're focusing on at the moment is reliability, and getting the KERS system functioning, which is completely new for us as a team, but not new for a lot of our engineers.

"Then you're going to see in Barcelona and Bahrain the things I would call the real performance steps, and I think it will be the same for Ferrari and Red Bull. They will have a lot going on in preparation for Bahrain."