"Going into such a huge event with so many variables with a 20-point lead or something like that, that would be hard work and definitely not ideal."
Whincup was only fifth fastest in Friday practice, though stifling temperatures in the mid-30s and high winds made the four sessions less of a true speed test than usual.
The fastest man in practice, Ford driver Paul Dumbrell, set his slick 1min 10.4085sec time in the third session.
Whincup only declared part of his hand in session four, setting the third fastest time in the 35-minute hitout for his best effort.
But most importantly as far as his weekend is shaping up, it was quicker than Lowndes was able to offer.
"It's super-hot conditions - the track temps are in the mid-40s and the soft tyre doesn't like the heat," Whincup said.
"We were literally four wheels sliding everywhere.
"What we're seeing on the timesheet is the one-lap time of everybody who was on a fresh set of tyres so, at the moment, I'm third on a fresh set.
"I'm pretty happy with that."
Whincup has turned around the advantage Lowndes held on him after Bathurst.
With 150 points on offer for the winner of each race, Whincup will seal the championship if he holds a 300 point-plus series lead come close of business on Sunday.
Sandown has been a happy place for Whincup with nine podium finishes in his past 10 races at the south-east Melbourne venue.
Ford swept the three fastest practice times on Friday, with Mark Winterbottom and Tim Slade second and third quickest behind Dumbrell.
- AAP
