Polyphony Digital president Kazanori Yamauchi sums it up best in Driving the Game, a hardcover coffee table book not sold seperately in New Zealand: "The simple philosphy of GT [is] high quality reality." This applies as much to the quality of the game world as it does to the accuracy of the tracks and the capability of the physics engine. For a console that dates back to last century, the quality of the reality in GT4 is set to leave the game and the console as a landmark combination of how far realism could go.

Yes, Yamauchi is happy to make it clear that the AI is at 1 or 2 per cent of where it should be to be believable, and that the arcade mode still has toned-down physics and that nowhere in the game does the handling model include calculations for each car's individual dampers. The first and last points are limitations brought about by technology, whereas the second is simply a matter of executive decision making for the good of the franchise, kinda like how it's easy to recover from the grass (although harder than in GT3 or Concept).

To put it simply, besides Yamauchi's own philosophies on sticking to what can be done well, GT4 is hampered not by resources or time, but only by the technological ceiling of the PlayStation 2. There is no doubt that GT4 would be similarly hampered on Xbox and GameCube (perhaps there would be online play on Xbox but that's all we could be confident about). One notable aspect of the way Polyphony Digital is creating the game world is by duplicating environmental textures which indicates it might not be using the PS2's revolutionary streaming and self-generating capacity for trackside objects such as trees. However, no two textures on the track surfaces themselves are the same. There is also that remarkable ability to produce backdrops such as the Grand Canyon, and with the impressive draw distance and overall visual and physics quality that is unmatched even on PC, it's hard to think all of this would be possible on any other machine.

One area of the PS2's architecture that has caused headaches is in its LAN functionality. Whether it was due to the i.Link's weakness in cost or as a port for hackers, or simply because PD didn't want to offer its LAN mode through two ports as did Free Radicals for TimeSplitters 2, there is no doubt that GT4's ethernet LAN mode has to be as difficult to use as it was to program. Forsaking the all-but-perfect Firewire hookup has left GT4 lacking in an area where it previously overcame the lack of AI. And without official online play we can only hope the next, online compatible version promised later this year will not only have great netcode, but that that will also improve LAN functionality.

Gameplanet has extensively tested the LAN mode from two to six players, and few tests have produced the same results twice. It's the same on the NTSC J version, and seems unrelated to the number of players hooked into the system. What we do like about the new LAN mode, however, is that now each player can choose his own tyre compound while features previously exclusive to GT Concept - such as LAN replays and assistance settings options prior to each race - have been retained. Changes we don't like include the inability to get out of LAN mode once in (particularly troublesome since you can't change options such as the number of laps in a race), and the inability for losers to finish if they are more than a few seconds behind the winner - previous GT games allowed over half a minute, which itself wasn't enough for those running competitions and Sony's PR material expressing hope of Gran Turismo LAN racing growing to professional level is hardly backed up by such a casual-style format.

We also wish we could enjoy the full physics of the Gran Turismo Mode in LAN play, but alas it comes under the Arcade umbrella. But it's still fantastic and while no mode is able to offer that extra detail we mentioned about individual dampers, we know it's coming when more power is available to the developers along with damage modelling and more than six cars on the track.

Polyphony is the first to acknowledge the heavy restrictions on what it is able to do on PlayStation 2, and it is this accepting attitude that has seemed to allow it to get so much out of the machine. Where other developers have repeatedly come up short, PD has completely rewritten both the physics and graphics engines for GT4 even after GT3 and Concept took the old engines so far.

Even the trick of getting progressive scan and high-definition modes in the NTSC versions of the game stretches what was thought technically possible on the PS2. Although not pure modes, the improvements they lend to the visuals put the latest PC racing sims to shame.

However, falling short of progressive scan or high-def graphics in the PAL version only adds to the game's disappointing lack of advancement. While GT4 has kepts its boundaries close to previous games in the series, the overall impression is of a game less accomplished than ever.

While the AI is constantly adjusted to remain competitive with the player (beating the hardest setting in fact puts you in a league amongst the world's best real-life drivers), there is nothing smart about its driving ability. Cars simply drive with little awareness of others, and even objects such as walls. All this extends to the B-Spec management mode but thankfully in the PAL version one is at least able to jump in behind the wheel or swap with the autopilot during a pit stop.

If you're as disinterested in any participation of the AI in your Gran Turismo experience as we are, then unless you just want to take photos all day (the Photo Mode is a magnificent addition to the game and one of those rare features that genuinely extends the gaming spectrum) you have little else to do as far as competition goes apart from racing your own ghost and posting time trial codes online. And as far as we're concerned, that's exactly why the LAN and online aspects of racing games should be seen as nothing less than crucial. Unfortunately not only does GT4 require your PC in order to play online, but the network performance whether online or in LAN play is a real problem.