V8 Supercars Championship points leader Mark Winterbottom emerged fastest of the 29 cars contesting the opening practice session for this weekend's SkyCity Triple Crown at Darwin's Hidden Valley Raceway.

Winterbottom's Ford Performance Racing BF Falcon bumped multiple champion Mark Skaife from the top of the timing screens with barely four minutes remaining in the day's two-and-a-quarter hours of practice, as teams struggled to enjoy their once-a-year invasion of the Northern Territory track. All were faced with the added difficulty of tuning their suspension to cater for a brand new control tyre introduced by Dunlop, while both Winterbottom and Skaife admitted to a learning curve compounded by variable levels of grip.

"There's not much difference between Mark and I, but I'm still complaining about the car, so there is more to come," Winterbottom commented, "I didn't feel that there was much difference between the old and new tyre as they feel similar; although the new ones appear to provide better longevity even if we can't assess that yet."

Skaife, deprived of fastest by a mere 0.0022secs, admitted that there was still work to do before his Toll HRT team was able to get a handle on the latest rubber.

"We were pioneering a bit on the new tyre and you can't really draw a comparison - yet," he said, "This is quite a complex circuit to do a good lap but, if you brake a little later and get better exit speed, there is a great reward in lap times if you are aggressive. Introducing the new tyre gets your brain around the job of setting up the car."

Third quickest was the Valvoline Cummins Commodore of Lee Holdsworth, anxious to put behind him a recent run of misfortune. Aiding and abetting his speed was the debut of a Walkinshaw Performance motor similar to that employed by the HRT and HSV outfits.

"It certainly has more horsepower than what we have been using," the rising star admitted, "It is the first time that I've been here in a VE, first time on the new tyre and with the new motor so to be third already will hopefully put us back in contention.

"You have to be patient with the throttle and I'm not used to it yet. The motor may have a bit more power but takes longer to get to full throttle so it is a balancing act. We struggled with the handling at the start but did a major change which made a lot of difference at the end. [Team-mate] Michael [Caruso] made a change which we copied, but I went backwards so we altered the roll centre setting and transformed the car."

Reigning champion Garth Tander, Will Davison, Jamie Whincup, Steve Richards, Craig Lowndes and James Courtney were next in line; all less than a quarter of a second shy of Winterbottom's lap time, with Ford having six of the nine quickest cars. Tenth was Todd Kelly's Jack Daniel's Commodore, which came in ahead of Courtney's teenage team-mate Shane van Gisbergen, who again impressed despite having never raced in Darwin previously.

"I used a computer version of the V8 Supercars game, as well as data compiled by Stone Brothers Racing since 2003, and viewed footage from last year's telecast," the Kiwi commented, "You get fairly close to reality with the quality of computer games these days, but it all looked different when I went for a walk of the track yesterday morning."

The hot temperatures failed to affect any of the drivers coming from the frigid southern states.

"Coming up here from Melbourne is a fair difference but, today, I didn't feel too bad," Skaife said, "Perhaps we've made a good job of making the cockpit cooler than previously."

The day's only real casualty was New Zealander Fabian Coulthard, who lost control of his Glenfords Falcon around at the same corner - Turn Eight - where Courtney overturned twelve months ago. Damage was mostly confined to the left rear quarter and boot lid of the Falcon, although the car was sidelined for the remainder of the session.

"I locked the rear tyres on the way into the corner and then missed every sand trap, ending up doing a '180' backwards into the barrier," an embarrassed Coulthard said, "The damage is mostly cosmetic and all that I have lost is some valuable track time - and my pride!"