New analysis of data from the most recent event of the Repco Supercars Championship has raised the question of whether all is as it seems in the ongoing parity debate.

Chevrolet teams have certainly dominated in terms of headline results through three events and nine races to start the first season of the Gen3 era, with a Camaro first to the chequered flag nine times and on pole position seven times.

The formline has led to a not uncommon view that the Ford Mustang is on the wrong side of a disparity between the two cars, and that cannot be ruled out.

Indeed, as revealed by Speedcafe, Supercars is looking into the feasibility of commissioning a transient dynamometer in Victoria for further testing of the Gen3 engines, amid a theory that the Mustang’s is somewhat hamstrung due to greater inertia.

However, it should be stressed that no outstanding disparity has been proven yet and, as has been pointed out to Speedcafe, only two of the six Chevrolet teams have been doing the winning.

They are Erebus Motorsport and homologation team Triple Eight Race Engineering, which, likewise, are also the only two Chevrolet outfits with pole positions.

Are they just doing a better job than their four stablemates and the five Ford teams?

Analysis of lap times at the Wanneroo event supports the notion that it may be that simple.

In qualifying, the Mustangs were in fact faster than the Camaros on average in two sessions out of three.

The average of the Camaro drivers’ respective fastest laps in Qualifying for Race 7 was 54.724s compared to the Mustang drivers’ 54.733s (noting that the respective fastest laps in this session are not necessarily drivers’ actual qualifying times, such is the nature of the knockout format).

However, in Qualifying for Race 8 and Qualifying for Race 9, the Blue Oval brigade has the upper hand. Mustang drivers averaged 54.526s versus Camaro drivers’ 54.631s in the former and 54.482s versus 54.573s in the latter.

If we rank fastest laps, there is virtually nothing in it in terms of average position across the three sessions – one is a dead heat – although, again, the Mustang contingent is slightly better off overall.

Camaro drivers averaged the 10.545th-fastest lap in Qualifying for Race 7 versus 12.636th for Mustang drivers, but the next session is 12.818th versus 10.455th and then 11.727th for both in the final qualifying hit-out of the Perth weekend (calculated using top 11 Camaro drivers only, given there are 14 Camaros and 11 Mustangs in the field).

Fastest lap times in qualifying sessions

Qualifying gives us a good indication of raw speed and is largely removed from the vagaries of strategy and whatnot although, in the Supercars Championship, points are only awarded in races.

It is also in races where the possible engine inertia disparity could manifest itself in a tendency towards increased tyre wear for the Mustang drivers, so one theory goes.

Looking at lap times again, the Mustangs appear competitive, if not quicker generally – on the basis of both average fastest lap time (ie average of fastest lap time for each driver) and average 50th percentile lap time (ie average of each driver’s 50th percentile lap time, which protects against skew by outlier laps).

In Race 7, the Mustangs are quicker on average fastest lap time and average 50th percentile lap time by a tenth, and average a better position in terms of fastest lap time rankings.

Race 8 is closer but Mustang drivers prevail on average fastest lap time and average 50th percentile lap time again, although this time it is Camaro drivers with the higher average in fastest lap time rankings.

In Race 9, there is virtually nothing in it in terms of the times, but the Camaro average position is better again (reiterating that this is based on the top 11 Camaros on the basis of respective fastest laps).

Fastest lap times in races

* Rounding error

Wanneroo is the best and arguably only track from which we can glean an impression of parity (or otherwise) at this point in time, given it is the only venue at which the field has raced with the new Camaro centre of gravity specifications and new Mustang engine map.

Supercars, it should be noted, is a technical parity category but not a sporting parity category.

Rule A1.4.2 of the Operations Manual reads, “The Supercar Category is underpinned by the governing principle that to the extent that it is possible, Competition will take place between the different makes and models of Cars as equalised by the technical parity mechanisms enshrined in the Rules.”

Furthermore, Rule A1.4.4 reads, “The Category is not about equalisation of the abilities of participating Drivers and/or Teams. It is up to individual Drivers and/or Teams to compete to the best of their abilities under the principle of technical parity.”

The above figures, however, are a manifestation of both the cars themselves and the abilities of the participating drivers and teams.

Supercars has more precise data, which can account for a range of variables.

As such, the figures here are not the full story, but they do suggest that the Mustang might even have the edge and that, if the Camaro does indeed have an advantage, it is likely a slim one.

Event 4 of the 2023 Supercars Championship season, the Ned Whisky Tasmania SuperSprint, takes place at Symmons Plains this coming weekend.