Videos promoting new car DLC for Gran Turismo 5 have revealed circuits not yet available in the PlayStation 3 racing game, causing fan speculation that the new tracks are either on their way as DLC or are in fact early looks at new tracks to feature in Gran Turismo 6.

The video reveal for the 2014 Corvette Stingray - available as a free download for GT5 - features the Willow Springs track. This relatively short track set in the California countryside has never been available in a Gran Turismo game.

In addition, the reveal of the new Acura NSX Concept shows what appear to be the Seattle and Apricot Hill circuits. Both circuits will be known to Gran Turismo fans, but have yet to make their way into Gran Turismo 5.

It's not clear if the newly revealed tracks will appear as a DLC track pack for Gran Turismo 5, or are they indicators of what is to come in Gran Turismo 6?