Tander was snapped up to partner the Kiwi in the Red Bull Holden Racing Team's #97 ZB Commodore after losing his drive at Garry Rogers Motorsport in the off-season.
With Craig Lowndes having been placed alongside Jamie Whincup in the sister car after his own full-time Virgin Australia Supercars Championship career came to an end, van Gisbergen is the only one of Triple Eight Race Engineering's quartet to have not yet won the Great Race.
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Van Gisbergen won the Supercars Championship and Bathurst 12 Hour in 2016, but finished second to his former team, Tekno Autosports, by the closest competitive margin in history of 0.1434s in that year's 1000.
That near miss came two years after he led on his way into pit lane with 11 laps to go and stalled the Tekno Commodore, with the starter motor failing when he attempted to refire it.
“He's been so close there a couple of times in the past that really it's not a matter of if, it's a matter of when for Shane,” said Tander at a media event for Supercars streaming partner Kayo.
“He's certainly got the runs on the board and he's achieved success in every other aspect of Supercars; it's only this last one at Bathurst.
“The only problem is, Bathurst is not just a small thing, it's quite a big deal, so if I can be part of that, and help him achieve that, it'd be fantastic.”
Team manager Mark Dutton believes that Tander is a fit for van Gisbergen's driving style, having had a chance to observe the three-time Bathurst 1000 winner at test days and in the Additional Driver sessions at Symmons Plains, Winton, and The Bend.
“We've had a chance, as had every other team (in the Additional Driver sessions), to establish what they liked and in all of those Garth's been very comfortable in Shane's car and Shane's set-up,” Dutton told Speedcafe.com following Triple Eight's pre-Bathurst test.
“Today (the test day) was the same. We're really happy with both their performances there.
“GT has slotted into the team perfectly, couldn't be happier. When you've got those sort of calibre drivers you definitely can't be complaining about your driver line-up.”
Meanwhile, Tander has backed suggestions from leading full-time drivers that this year's Bathurst 1000 will play out at record pace, weather permitting.
Shell V-Power Racing Team's Scott McLaughlin is confident that his practice/qualifying lap record from the 2017 Armor All Top 10 Shootout will go, while he and van Gisbergen both think the race record could fall.
“I think if the weather conditions are favourable in the lead-up to the event, and through practice and qualifying, we'll see some very fast lap times,” added Tander at the Kayo event.
“As far as the race goes, if there's not too many Safety Cars, we will see a record time as far as how quick we'll get the thousand kilometres done, because I feel like the cars will be much faster at the mountain.
“The quality of the drivers goes up every year, so we shouldn't see as many Safety Cars, which obviously slows the race down, so if the weather's favourable, it's going to be a fast weekend.”
The 2019 Supercheap Auto Bathurst 1000 event starts with three hour-long practice sessions on Thursday, October 10.