Speaking during an interview with GT Planet, Yamauchi-san revealed that the only major difference between each version is the loading times, which isn’t a surprise considering PS5 is equipped with an SSD.
In a racing game, you can adjust the level of detail. Technology wise, it is a very scalable game in terms of maintaining the frame rate and everything else. We found that we were able to make a PS4 version and a PS5 version without dropping any quality, so that’s why we decided to do both at the same time.
The loading time is so different between the PS4 and PS5 that it’s a completely different experience. That’s just something that’s unavoidable between the two.
Gran Turismo 7 is pencilled in for a PS4 and PS5 release on March 4, 2022.
[Source – GT Planet]