Fans who have been waiting for "Gran Turismo 7" may need to wait longer as various sources report that its release may be pushed back to 2017.

According to website Breathecast, the franchise's creator explains that they are still in the process of making the title and won't be able to release the game this year.

The seventh installment to the long running racing series promises to have major improvements for its PS4 release.

Cars that have appeared in previous installments will be retained, according to creator and Polyphonic Digital CEO Kazunori Yamauchi.

"I doubt we'll be throwing away the standard cars," Yamauchi told Eurogamer last year. "In the meanwhile, some of those cars we may be able to make into premium cars as they become available - but basically we're more focused on increasing the number of premium cars."

He also mentioned that improvements in audio can be expected, explaining that the sounds in "Grand Turismo 6" have improved, but "most of the work will be done in "Gran Turismo 7," adding, "the high quality of data that we have being rendered on the PS4, I think is going to make an incredible difference."

To date, "Gran Turismo 6" is the only game to get a certification from the FIA  for the 3D modeling of international race circuits. To test the accuracy of the tracks, Polyphony has announced that they will hold a special FIA Online event this year.

"It was not until we completed the tests between our track data and the game's track data that we fully appreciated the level of work and attention to detail that goes into the development," said FIA Head of Safety Jacques Berger. "It was not just the tracks that have been precisely mapped out, but also the surrounding landscapes such as the run-off areas, grandstands and buildings."