Turn 10 is "running out of improvements" to make on the Forza series.

Forza franchise director Dan Greenawalt told VideoGamer.com at E3 that the development team has "proven" that it can deliver a "simulator no-one else can touch".

During Microsoft's E309 media briefing last week, Greenawalt took to the stage to confirm the latest iteration in the Xbox-exclusive racing sim, Forza 3, would be released this October.

Greenawalt said: "Basically we've proven ourselves, that we can deliver a simulator no-one else can touch. For this version we made improvements but we're actually running out of improvements to make because no-one else is doing the stuff we're doing.

"I've made my job much, much, much harder. And that was the goal, right? In this version we're saying we'll perfect the racing game and start taking it beyond. What other racing game features do I want to do? Yeah there are a couple of little things, very small. They're not easy, but they're small."

When asked if Forza can improve graphically on the Xbox 360, Greenawalt revealed that because Turn 10 is a first-party developer it's able to "reap the benefits" of what other developers have learned while creating games for the system.

"It's like Tetris and you're learning how to fit the pieces in better," he said. "It takes time and you've got to just keep massaging it and massaging it until you get more pieces in. Now, it is an exponential curve. So in the first year you learn a lot. Next year a little bit less. We're now four years into this cycle. Have things started to stabilise? Yes. And we're reaping the benefits of a lot of what Epic has learned, a lot of what Bungie has learned, and some of the beautiful games like Mass Effect, what BioWare learned. We reap the benefits of that."

He added: "The truth is there will be continued improvements. As first-party, we're not cross-platform, we can use every improvement that's made. So if someone figures out how to make... you name it... something they've done specifically for their game, we can figure out a way to make that work on ours."

What improvements would you like to see in the Forza series? Let us know in the comments section below.