Button's chance of fighting DTM's best is out of his hands

Formula 1 world champion Jenson Button opens the press conference ahead of the first DTM-versus-SUPER GT racing weekend by telling everyone to give themselves a "pat on the back" for getting the unified Class One to this stage.

He's right, if only because the next step for DTM and SUPER GT looks daunting as the practice sessions begin at Hockenheim, with no-one any the wiser as to how the two different series will match up.

The Japanese SUPER GT contest doesn't fully adopt the DTM's Class One regulations until 2020, which creates the problem of one series aimed at endurance (SUPER GT) and one at sprints (DTM). It's been a topic of intrigue since the joint-race details became clear.

SUPER GT has extensive aerodynamic development, whereas the DTM puts a premium on common parts. DTM has DRS and push-to-pass, while SUPER GT has a highly competitive and open tyre war.

While SUPER GT manufacturers are loathe to release full figures, their engines reach around 700bhp in qualifying trim compared to figures of 600-650bhp in the DTM. The minimum weight of a DTM car is 1070kg compared to SUPER GT's 1020kg - although Button's Honda is 1049kg due to a non-Balance of Performance adjustment because the NSX is mid-engined. This is why, despite the DTM's well-known dislike of it, BoP will be used during the race weekend to even things out.

DEKRA, the DTM's technical partner that is overseeing the BoP process, has its hands full. Ideally, Thursday would have given DEKRA plenty of information when Button's Team Kunimitsu Honda, the NISMO-entered Nissan shared by Ronnie Quintarelli and Tsugio Matsuda, and the TOM'S Lexus of Nick Cassidy and Ryo Hirakawa hit the track.

But the two hours were filled with dry, wet and damp running on a green track that hardly improved due to the limited number of cars on track. Times were not released and there was no footage of the action. But a cheeky bit of stopwatch spying revealed that Button set a low-1m31s effort, while Cassidy claimed to have lapped in around 1m30.9s. Continued timing showed laps varying from low-1m31s to high-1m35s.

That paled in comparison to BMW driver Philipp Eng's pole position time of 1m28.972s in dry conditions at Hockenheim for the season opener back in May. While it's not the most representative comparison in terms of conditions, weather and temperature, it underlines the task DEKRA and the DTM/SUPER GT have to overcome.

With just two hours of running on Thursday, there was little in the way of time for long runs, meaning the SUPER GT teams will be at a significant disadvantage at Hockenheim

"It's going to be tough because it's wet," says Button. "We tested and the circuit was very green. I think the lap times were OK, I mean way off of qualifying lap times earlier this year at Hockenheim, but we don't know the improvement of a race weekend with the circuit gripping up. There's only three cars running."

It's understood that the BoP can and likely will be adjusted through the weekend, likely in terms of weight and engine-air-restrictor size, but there are also elements beyond the stopwatch to consider. One DTM team principal noted the SUPER GT cars were struggling with oversteer, while others suggested that, even without DRS and push-to-pass, the SUPER GT machines look to have an advantage on the straights.

The hope is that these factors will keep the cars close enough for BoP not to be needed, something the DTM has been confident will be the case next year, when the 2020-spec SUPER GT cars move closer to the DTM's Class One set-up. One aspect that may help is that the three SUPER GT squads will move further along the huge learning curve with the Hankook tyre, mandated by the DTM.

With just two hours of running on the Thursday, there was little in the way of time for long runs, meaning the SUPER GT teams will be at a significant disadvantage at Hockenheim.

"I hope in a few hours we can be close, but in Super GT we have the tyre competition war," says four-time SUPER GT champion Ronnie Quintarelli. "The grip from tyres [in Super GT] is really amazing because you can adapt the compound to track temperatures and situations.

"For us, we share the cars between two drivers and there is not much time to drive, so in the test we could get a few laps in dry conditions and importantly collect the data. Today's [Friday's] practice is rain, and we have to start from zero again. So not much time."

The three SUPER GT squads are getting support from Hankook to help shortcut the disadvantage to the DTM teams, but it will only help so much. As Button points out, the race format itself will prove a headache for the SUPER GT teams, with Button already stating that his Honda squad needs to sharpen up on pitstops - now it will be required to do a tyre change in around five seconds, as opposed to a 40s stop that includes refuelling and a driver swap.

"There are many different things that people probably don't realise are different because they're normal here [in DTM]," says Button.

"We don't have the Hankook tyres, that's different for us. We have a tyre war in Japan with four different manufacturers, so for us to get used to another tyre is difficult for all of us.

"But also, we've never done standing starts in a SUPER GT car, they're all rolling starts. The safety car rules are different. We don't have DRS or push-to-pass, and also the pitstops - they're 40 seconds long in SUPER GT!

"So there's so many different things [to learn]. It's fun learning new things but I think for the mechanics, it's tough for them and team personnel, rather than us. I think we're pretty much there, there's still some things we need to scrub up on - one of them is pitstops, but we'll try our best."

SUPER GT's season is still ongoing and none of the drivers prepared in a simulator ahead of Hockenheim. Button jokes he was "changing nappies" after the birth of his son, and Matsuda says he learned the track on a PlayStation

Button is in a unique position compared to his SUPER GT rivals in that he will compete in both races, whereas Nissan and Lexus will split the running between their respective two drivers each. While that means all drivers will have a level of personalisation in terms of in-car set-up they would not have in SUPER GT, Button can adapt the car to himself.

"We share the car in Japan," he explains. "I'm 1.83 metres tall and Naoki [Yamamoto, Button's co-driver in SUPER GT] is 1.63m, so we're quite different in height! So to set the car up within the cockpit is very difficult for both of us.

"So, things like that, now I can build the car around me. I have a different seat, the steering wheel is in a different position, so I'm a lot more comfortable in the car, which is nice. And I also get to have more practice, which is lovely."

The press conference has almost passed without mention of BoP, until Autosport asks Button for his expectations in how the series will balance the two concepts. "We're trying to get the tyres working, which is a big thing - I don't think any of us are there yet with the tyres," he says. "I wouldn't say we're quicker than a DTM car. When you look at the car, we're more technically advanced in terms of the aerodynamics and what we are allowed to do, and that's not showing on the track. So, we have to see.

"I think the inexperience with the tyres outweighs the downforce benefits of a SUPER GT car, which is great because it makes the racing good, and I feel if we were out with the DTM cars in the test we wouldn't have been quicker than them and maybe now we could have caught up.

"With the BoP? Who knows, I've not heard anything. That could change. Today is wet and maybe the whole weekend, and then we can get a good understanding."

That's further compounded by the fact that while the DTM can focus on a season finale in which almost all the major titles have been secured, SUPER GT's season is still ongoing and none of the drivers have prepared in a simulator ahead of Hockenheim. Button jokes that he was "changing nappies" after the birth of his son Hendrix, and Matsuda says he's learned the track on a PlayStation.

With spare parts at a premium, we're unlikely to see titanic wheel-to-wheel battles, although Eng and Button came too close for comfort in the opening minutes of the first free practice session. Meanwhile, Cassidy repeated Sebastian Vettel's 2018 German Grand Prix Sachskurve crash and Matsuda had an off at the same corner in his Nissan. Those two managed just 17 laps between them compared to Button's 16, with the British driver's best time good enough for 16th, 2.6s off Timo Glock's pacesetting time in wet conditions.

Those are the early flashpoints of the first real test of the Class One link-up. Success here gives the perfect platform for the true showcase next month at Fuji - the second joint race - but the only certainty is the growing pains both series will go through to make Class One the global phenomenon it believes can change motorsport.