The Gran Turismo series inspires devotion among fans like few others, especially in the world of hardcore driving simulators. ‘The Real Driving Simulator’, as it’s called, has become a genuine event for those obsessed with peeling around some of the world’s most exciting tracks in hundreds of the world’s finest cars. As such, Sony and Polyphony Digital seek to wring as much money out of the franchise as possible.

To this end, a ‘prologue’ edition of the game has been released before every genuine Gran Turismo title since the fourth incarnation of the game made its debut on the PlayStation2 back in 2005. It’s a way for the most devoted of fans to get their hands on a portion of the game before the full-fat product is released - in return for a fistful of cash.

It’s a demo, then, albeit one you pay for – and one that, oddly enough, had its own demo back in 2007. It’s one of the best demos you’ve ever played, though, as it contains a sizeable chunk of the finished title.

There’s a handful of tracks that are, of course, correct to the last lick of paint on the tire walls and pebbles in the run-off areas. Several real-world circuits are included – such as the Fuji and Daytona International Speedways and famed Suzuka – alongside some familiar, fictional tracks that have featured in Gran Turismo for years. Veterans will be familiar with the High Speed Ring, for instance. They’re a joy to drive on, and there’s barely a fault to be found here. Recreated perfectly in stunning high-definition, they fuel the motoring fantasies of millions of amateur racing drivers.

And then, contributing to these fantasies, there’s the cars. Thirty-seven cars are included in the initial game, and more have been added with every update – of which there’s been three so far. Each motor has been feverishly worked on to create a perfect recreation of the real-life cars and, as usual, they’re fantastic.

Handling is, along with the graphics and extensive garage, one of the cornerstones of the Gran Turismo franchise – and it doesn’t disappoint here. Each vehicle has a distinct personality and various handling nuances that, like any car in the real world, will only be picked up through extended use. The myriad tweaks you can make also suitably alter the way the cars feel on-track. For those wanting to get the most out of the game, though, a steering wheel would be a wise investment – as any serious driving game is undoubtedly better with one rather than with a pad.

The power of the PlayStation3 undoubtedly brings numerous benefits when compared to the older games. Graphically, it’s one of the best racers in the world: cars gleam as if they’re fresh off the forecourt, and the tracks are recreated to within an inch of their lives. On an HDTV it’s as if you’re hurtling around Suzuka or London for real. The added power of Sony’s console also means that more cars, modes and features can be included – Gran Turismo TV is a promising video-on-demand service that will eventually offer car shows, reports and content for viewing anytime, and the promise of episodic content will further increase longevity in the finished game – although the developers have recently admitted that it may not see the light of day in 2009.

One of the most highly-anticipated features is one that Gran Turismo fans have been clamouring for since the first release, way back on the PlayStation1, in 1998: damage. It’s not in the retail version, but will be added in a patch soon, according to Polyphony Digital. I’d question, though, if it’s worth buying the Prologue and then having to add the damage patch further down the track. While downloadable content and patching is undoubtedly a step forward, increasing the longevity and quality of games, by the time the Prologue patch appears you might as well just wait for the genuine release of Gran Turismo 5.

For all of its excellence, though, I can’t banish the feeling that this prologue edition is more of a money-making exercise than a genuine teaser: a price of £25 – roughly $50 – is higher than any of the previous Prologue titles and steep for what is, essentially, an extended demo. Couple in the price of the finished game, which is due to arrive later this year, and you can easily spend over £70 – about $140 – on the latest incarnation of the Gran Turismo franchise.

You’ll enjoy this, then, if you’re a Gran Turismo devotee who demands as much hyper-realistic track action as possible – and simply can’t wait for the full release. There’s no doubt that the list of cars, mind-blowing graphics and fantastic gameplay ensure that Prologue would be a decent product in its own right if the promise of the full game wasn’t so forthcoming. Bear in mind, also, that downloadable updates arguably negate the need for a product like this even more, and it’s expensive for an extended demo. One for the hardcore fans only.