Brodie Kostecki has made an almost immediate impact on Supercars parity since defecting from GM to Ford.

Kostecki, the first champion of the Gen3 era, was always going to be a fascinating yardstick for the parity issues that have marred the latest generation of Supercar.

From the GM side, much of Ford's failings for the first two years were blamed on teams and drivers not doing a good enough job.

It was an ambitious notion at best when you're talking about drivers like Cam Waters and Chaz Mostert, but a well worn theoretical path nonetheless.

However, Dick Johnson Racing nabbing Kostecki from his ultimately unhappy home at Erebus created the perfect test.

Kostecki's Gen3 credentials can't be argued, and for good measure he bought not one, but two race-winning engineers from Erebus with him.

And moved straight into an Erebus-built chassis. Leaving the bodywork and engine as the major variables.

Aero concerns do seem to have disappeared since the costly wind tunnel testing at the end of 2023, but a similar exercise in offshore transient dyno testing just has not reached the same clarity with engines.

Ford drivers have continued to complain about the quad cam Coyote V8 not being up to scratch, and with Kostecki joining the fold, they have a powerful new voice.

Kostecki is not only a brilliant driver, but technically minded like no other driver in the field. He quickly recognised that yes, there was a deficiency with the Ford engine. And started lobbying for change.

There is some conjecture in the paddock about the extent of Kostecki's influence, but credible signs point to it being significant.

Armed with his theory about temperatures, he is thought to have started to campaign for change around Albert Park.

In Taupo he met with Supercars head honchos to put his case forward, and subsequent testing revealed that yes, there are in fact differences in the engines at different temperatures.

And the hotter temperatures more prevalent in racing scenarios is where the Ford struggles.

It is interesting that this evaluation work didn't require a transient dyno, or even the barometric upgrades that are being made to Supercars' own testing equipment now. It just hadn't been checked as thoroughly as it has now.

While it was difficult to spot any real difference in the cooler Tasmanian conditions, and Perth is likely to coolish as well, Darwin and Townsville will be interesting. Darwin in particular has long been a GM stranglehold.

Remember that Adelaide is usually very hot too. And that's where the title will be decided.

Kostecki is adamant that more work has to be done, and the elevation theory for Bathurst is still one to be checked, once those dyno upgrades are done.

But to see him have such an impact in such a short time frame is fascinating all the same.