It's nearly that time again - a Gran Turismo release. It's 2008, and the prologue to the fifth chapter in Sony's amazingly successful racing series will be speeding onto kiwi shelves shortly. The question simply remains - what can you expect this time around?

We've already been given a release date of 28th March (or the 27th if you download it from PlayStation Network), and thanks to a lot of chatter on the internet we can go over what content is known to exist in the final release.

There will be a total of 71 cars, including the likes of the Nissan GT-R, Aston Martin DB9 Coupe, Ferrari 599, Subaru IMPREZA WRX STI and even classics like the Ferrari 512BB and a 1960 Corvette. All cars are from the U.S., Japan, Germany, France, Italy or Great Britain, and are rendered with over 200,000 polygons each, as opposed to 4,000 for Gran Turismo 4. The game will also feature a highly realistic in-car view, showcasing each car's dashboard, steering wheel and gear stick in stunning quality.

There are six tracks in total - High Speed Ring, Daytona, Fuji Speedway, Eiger Nordwand from Gran Turismo HD Concept, Suzuka Circuit and a square section of central London from Haymarket to Charing Cross Road. There have been rumours floating around that the BBC has commissioned the Top Gear Test Track for Gran Turismo 5 - unfortunately this does not appear in Prologue, so you'll probably have to wait another year to see if you're faster than Clarkson in a Suzuki.

Your garage has been enhanced - you now will have access to not only your fleet of vehicles, but a personalised homepage with calendar, clock, and map/weather conditions of major tracks worldwide. You will also have access to Gran Turismo TV, where you can view historic video footage provided by manufacturers, and eventually Top Gear episodes.

The "Arcade Mode" has been greatly enhanced, and now features one-off races, Time Trials and Drift Trials. You can play solo or with a two-player, horizontal split-screen.

We've also learned that there will be no collision damage, however it has not been ruled out for a future Gran Turismo release. It seems that Polyphony Digital wants to include vehicle damage, but only when they feel they can do the concept justice. At least that's their excuse, because bowing to pressure from car manufacturers isn't always something you want to admit to.

The PlayStation Network version of Gran Turismo 5: Prologue weighs in at 1.9GB, not exactly huge given the level of complexity added to the 1080p graphics all designed to run at 60fps. It seems that in order to keep the download small, the cinematics will be left on the server until you elect to download them from GT TV. You can choose to download the opening movie at any time, and when you finish Event series you're told that you can now download the end movie from the in-game high-definition TV download page - both movies will be included on the Blu-ray disc version of the game.

The Quick Tune feature, new to GT5, allows you to adjust power, weight, tyre, aerodynamics, ride height, spring rate, damper, toe angle, camber angle, brake balance, traction control, max turning angle, ABS, torque balance and gear ratios. The Quick Tune page also shows you graphs of power/torque and gear ratio to help you see what you're doing. You can store different configurations to switch between in real-time during races, and these configs can be assigned to buttons on the Sixaxis or Driving Force GT steering wheel.

You will have the choice between "Professional" physics ahead of the "Standard" mode, and a host of driving aids are provided to assist you in learning each track. The traditional driving line is retained, and as a bonus you will see target speeds over the far end of red braking sections to help you work out when to accelerate.

It appears the "Online Racing" mode is fairly crippled in Prologue, with no friends list and a fairly basic link-up to play against a total of sixteen players. Polyphony plan to add more options at a later date, so hopefully this will allow GT5 to compete ably with the likes of Forza Motorsport 2 on Xbox 360.

We're starting to see the first reviews arriving for the final release of Prologue, the majority of which claim that for what is essentially a demonstration of a game yet to be released, there is more than enough content to justify the price tag of $69.95.

It remains to be seen however if this release will do anything to increase PS3 sales - we can't help but think that the final Gran Turismo release will be required to effect any kind of mass revolt amongst the Xbox 360/Forza/Project Gotham fan base.