Retro style - with power

Engine: single cylinder, liquid cooled, 4 stroke, fuel-injected, 244cc
Max power: 22 bhp @ 8,500 rpm
Max torque: 20.2 Nm @ 6,500 rpm
Brakes: single 220mm discs at front and rear
Transmission: automatic
Top speed: 76 mph
Fuel capacity: 9.2 litres (including 2 litre reserve)
Colours: red, black, silver.
Price: £3,249

The courier who caught up with me at the eastern end of the Limehouse Link was charming, blunt and intrigued. "What have you done to that thing, mate?" he asked, peering from the saddle of an ageing 600cc Honda. "You pulled away from the lights like you were riding a real bike." The sleekly suited executive in his Porsche Boxster looked similarly taken aback and a lot less pleased.

It was luck. They would both have beaten me if they'd realised they needed to try. But the Vespa GTS250 is deceptive. It looks sumptuous in that ultra-nostalgic way Vespa have made their own. You just don't expect it to be quick as well.

Every detail in the classic steel frame is designed to stir memories of the 1950s. At first encounter it seemed to say, "Hello handsome. How do you fancy a sun-blessed jaunt down to Brighton with Eve Marie Saint on the pillion?"

Eve was not available, but a lady of similar vintage stopped to chat with me as I munched a sandwich in Notting Hill. "Oooh," She said. "Isn't it pretty? It looks like a real one. You know, before they stuck all the plastic bits on. Is that proper chrome?" She caressed the folding luggage rack behind the saddle. It is, and very handy too.

The same goes for the big storage space under the saddle. I got a spare open-face helmet and my knapsack in there as well as a strong security chain (essential when parking something so alluring in town). It opens at the press of a button on the front fairing. And there is a glove compartment too, with plenty of space for a mobile phone, wallet and map.

The dashboard is natty. A big analogue speedometer is complemented by an equally clear digital display giving constant readouts of time, air temperature, engine revolutions, fuel level, engine temperature and mileage. Together with the load-carrying capacity, this level of equipment suggests you could tour on the GTS 250. Vespa says you can. I am a sceptic. Even with its 12in wheels and excellent urban handling characteristics this is still a twist-and-go scooter. It would carry a couple for hundreds of miles, but they would be a lot more comfortable on a conventional motorcycle.

But that is a pedantic gripe. This is the fastest, most powerful Vespa ever made, a tremendously entertaining little bike that really is quick enough for short motorway journeys and extended trips down A-roads and dual carriageway.

In city traffic I was always at the front of the queue. Low speed handling is perfect for wriggling between tightly packed cars. I was only beaten from standstill by determined bikers on much more powerful machines. I have never had as much fun on a scooter. The GTS is sporty enough to respond to rough handling. You can drop it into tight bends at silly velocities and pop back upright smiling and secure.

Less irresponsible riders will be pleased to learn that it also meets the new and stringent 2006 Euro 3 regulations. Travelling on two wheels has always been good for the environment but this scooter allows you to feel positively sanctimonious. I rode 50 miles around central London on a third of a tank of fuel and I was pushing the GTS 250 hard.

The lady in Notting Hill asked the right question: "Is it well made or just fantastic to look at?" It is both. Vespa's build quality leaves little to be desired. A conversation soon developed about what kind of licence you need to ride a Vespa GTS 250. The bad news is that you need a motorcycle licence. That is because the courier was right. This machine has the performance characteristics of a small motorcycle.

There are bigger GT scooters. Some have engines twice as big. But none of the other rides in what is becoming a crowded market retain the classic scooter look as perfectly as this one.

The best summary came from a barman I encountered in Bermondsey who already owns a Vespa 125. He had heard about the new model, but my Dragon Red was the first he had seen for real. "Yes," he decided. "I want one. It is utterly modern, utterly retro and utterly desirable."