It’s a question that can be hard to answer given the number of variables in a Supercars endurance race.

A co-driver who ends up with a trophy or shoots to prominence on the TV coverage with a blaze of mid-race speed isn’t necessarily the best performer.

This is why detailed lap time data is digested by teams after the endurance races to help shape future co-driver signing decisions.

We’ve teamed up with data analytics firm The B Pillar to give insight into how the co-drivers really performed at Sandown as the countdown to Bathurst continues.

Sandown is a tricky event to compare driver speed, even more so than Bathurst, due to the use of the super soft tyre and the high-degradation nature of the surface. Outright fastest laps are therefore irrelevant.

An average time taken from the best 25 percent of a driver’s total laps is a typical performance measure, but we’ll use the best 50 percent here to better account for the need to manage tyres.

Cooper Murray was the best co-driver at Sandown by this metric; an average lap time of 1:09.825s putting him comfortably clear of the next best.

This emphasises the fact he is really the primary driver in the Supercheap Auto wildcard and that nominating Craig Lowndes for that starting role was a clever rule workaround by Triple Eight.

Murray effectively acted as the primary by finishing the race and was also among those to benefit from the controversial driver weight rules that advantage lighter co-drivers

Notably, Murray’s performance was such that not only was he the top co-driver, he was the fourth-quickest of anyone on the 50 percent metric, behind only Chaz Mostert, Will Brown and Broc Feeney.

As the below table attests, the next-best co-drivers were Feeney and Brown’s respective running mates Whincup and Pye, who were very evenly matched across several data points.

Garth Tander, Todd Hazelwood and James Moffat also upheld their billing as top co-driver picks, albeit with Hazelwood’s efforts including a costly brush with Whincup that punctured a tyre.

Russell, Jayden Ojeda, Fabian Coulthard and Tony D’Alberto completed the top 10 on this list, which Murray and Ojeda aside is made up of experienced hands.

At the bottom of the order is Sandown Saturday Super2 race winner Jack Perkins, who was mired at the back of the pack following an ill-timed first pitstop on a tough weekend for the Blanchard Racing Team.

Perhaps of even greater interest than the raw co-driver numbers is how each compares to their respective primary driver.

The old adage of your teammate being your best comparison is even truer for co-drivers in endurance races, where the very same car is being driven (albeit at different stages of the race).

For this we’ve simply taken each co-driver’s average lap time from the best 50 percent of their laps, above, and compared it to the equivalent data for their primary driver.

Wildcards Murray and Brad Vaughan show here as being significantly faster than their primary drivers, underlining that both were really the top dog in their respective Camaros.

Vaughan made his Supercars debut at Sandown just hours after taking a maiden Super2 Series race win, where coincidentally he led Murray to the chequered flag.

The only other co-drivers quicker than their primary counterparts in the 50 percent average comparison are rookie Aaron Cameron (compared to Aaron Love) and Tony D’Alberto (to Anton De Pasquale).

Those comparisons can be viewed as both a tick for the co-driver or a cross for the primary, as Love and De Pasquale both had difficult weekends.

Five more – Fabian Coulthard, Hazelwood, Ojeda, Declan Fraser and Tyler Everingham – measured up to within a tenth of their primaries on this metric.

Most of the star co-drivers, including Moffat, Tander, Whincup, Pye and Russell, are in the mid-pack here, between one and three tenths off their primaries.

The big outlier though is Lee Holdsworth, who between his own struggles and some subsequently blistering stints by Mostert, ended up over seven tenths away.

Holdsworth was among those to enter Sandown with little recent racing under their belt and will need to step up at Bathurst for Mostert’s chances in the Great Race and title fight.

Note: The Richie Stanaway/Dale Wood Penrite Racing Mustang is not represented here as an early engine failure meant co-driver Wood did not drive in the race.

The B Pillar is a UK-based data analytics business, focusing primarily on GT and endurance racing, covering more than 40 series across six continents. Their clients are drivers, teams, managers, and the media to provide discerning and applicable insights into driver and team performance.