Forza Motorsport 5's physics engine "wouldn't have been possible with last generation hardware", Turn 10 creative director Dan Greenawalt has claimed, telling to "just do the math" when asked whether Forza 5's physics will be more realistic than those of upcoming PS3 racer Gran Turismo 6.

"The things we're doing on the Xbox One with Forza 5 physically just wouldn't have been possible with last-generation hardware," Greenawalt told us at Gamescom earlier today. "Partially because there wasn't enough power, but more importantly the approach. We have a completely new approach to how we're doing physics and a new partnership."

Greenawalt explained that Turn 10 ditched its partnership with Pirelli for Forza 5 to team up with Calspan, a science and technology research company that tested huge numbers of tyres in order to provide in-depth analytics for Forza 5's handling.

"Calspan tested for weeks, and at the end of that they gave us millions of data points, and I have to admit, it was more than I was expecting," Greenawalt continued.

"I was a little bit like, 'Oh, okay...'. So I worked with them on how we would reintegrate that into our game so we could have all of these isolated variables and reconstruct them in real time. So when I say that we're doing things in this game that could not have been done last generation, I really mean it's on two axes.

"One, all these variables require power. We have power. The more important one is the approach. This approach, nobody is doing this. Not on the PC. Nowhere. Because you have to be, one, questioning your assumptions, and two, you have to be jumping into the deep end with partnerships, new approaches, and honestly throwing a lot of time and energy at it. To me it's a commitment to always be wrong. That's my favourite part of my job. I'm committed to always being wrong. So that means I'm always pursuing perfection and throwing things away. That's what made our entire physics so much better this time.

But does that mean Forza 5 will boast a more impressive physics simulation than Gran Turismo 6?

"Just do the math. Honestly," Greenawalt replied. "I don't know what their physics engine is. I know what mine is. What I know is my approach and the amount of power we have in the box allows us to do things that we certainly couldn't have done on the 360 and we didn't do on Forza Motorsport 4.

"I'm not playing their physics, but I think it's one of those things where there is physics involved in just what we're doing."

Forza Motorsport 5 launches alongside Xbox One this November, with Gran Turismo 6 following on PlayStation 3 on December 6.