Road Test: Volkswagen Golf 1.9 GT TDI 115 5dr [6 speed]

I must admit that I'm not the most technically minded of the Top Gear staff. If ever the topic of conversation swings around to torque or compression ratios, I'm the first to get my coat. So you can imagine my anxiety when presented with the VW Golf GT TDI PD - a car whose defining characteristic is a new 1.9-litre turbodiesel engine.

With something this significant, it isn't as if I can just gloss over the engine and offer a simple treatise extolling the virtues of the MkIV Golf - you've no doubt heard more than enough about that already. Fortunately, I came across a brilliant website with the gloriously inspirational name of www.howstuffworks.com.

Following an afternoon being pleasantly diverted by the workings of the internal combustion engine - and the toilet, telephone and fax machine - it was time to tackle the Scrabble nightmare that is the GT TDI PD. First up, PD is the abbreviation for the German Pumpe Düse - that's the new fuel injection system which replaces the highly-efficient TDI 110bhp engine. The ingenious bit behind the new system is that it combines the injector and pump into one unit for each cylinder, a method which gives much higher pressure. With me so far? Well, the higher injection pressures mean better mixing of fuel and air which allows more fuel to be burnt cleanly in each cylinder.

And how does this manifest itself in real terms? Well, whereas maximum power is only up to 115bhp on the new model - an increase of just 5bhp - torque is increased by a whopping 20 per cent. The 210lb ft at 1,900rpm offers more grunt than a Venus Williams forehand. OK, there's a little turbo lag, but the TDI surges ahead in excellent fashion. The 0-62 time may fall on slightly the wrong side of 10 seconds, but the hike in torque means that everyday acceleration - the 30-50-type stuff - is very brisk. Brisk enough for this to be the only Golf where traction control is fitted as standard.

However, the tale doesn't end at the Golf's off-the-line performance; in truth, it's even more accomplished at motorway speeds. Coupled to a six-speed gearbox, you can cruise sub-2,500rpm with plenty of torque on tap to kick on should the need or desire arise.

I'd happily give you the low-down on VW's six-speed, three-shaft layout gearbox, but I've got the learning bug and I'm off to read how the refrigerator works...

Tim Oldham