Championship leader tops first practice

Mark Winterbottom has begun the Castrol EDGE Townsville 400 in the best possible fashion, topping the first session ahead of Tim Blanchard.

Winterbottom -who is a one-time winner at the street circuit - recorded a 1min13.6126 lap with four minutes remaining in the 30-minute session, in his Pepsi Max Ford Falcon FG X on hard tyres.

Close behind on the Dunlop soft tyre was Tim Blanchard, driving for Lucas Dumbrell Motorsport, a team thathas been consistently punching above its weight this season.

Shane van Gisbergen recorded the fourth fastest time, behind James Courtney, but retired in the garage during the session with a nasty vibration in his TEKNO Commodore.

Defending Champion Jamie Whincup -the most successful driver at this circuit - came home 19th, two positions behind Red Bull teammate Craig Lowndes, and spoke about the engineering switch on his car this weekend, with Mark Dutton returning to the race engineer role for Townsville.

"'Dutto' is on the radio, we're an engineering group so nothing really changes behind the scenes, but Dutto is back talking to me on the radio," Whincup said.

"We had to make some changes, it was critical, we are well down the order."

Whincup said the decision did not come from him, but was determined by the group.

"No it was made as a group I don't make any major calls... we had to do something so hope it's the start of a better performance from now on."

Chaz Mostert was fourth in the order with Scott McLaughlin, Michael Caruso, James Moffat, Nick Percat and Scott Pye completing the top 10 in the 30-minute first session.

Click here for full session results.

The revised format for the SuperStreet event sees two more practice sessions for the V8 Supercars today, with the second kicking off at 10.45am EST.