Forgive me please as I challenge you with an old riddle that fooled a few friends: what's heavier - a ton of coal or a ton of feathers?

Simple, isn't it, but it came to mind while driving through Liverpool in a Brabus-tuned Mercedes Benz Smart two-seater recently. Following me was a BMW M5, prompting the question: which is quicker at 30 mph - the Smart or BMW?

Are you with me? It matters not in congested urban traffic how much power you have at your disposal and how menacing the car. In this case the Smart comprehensively out gunned, out parked and yes, out smarted the mighty M5 as I reached - and kept - the first precious parking space (anyone who's tried parking recently in Liverpool city centre will know what I mean).

So despite giving away three seats, a few hundred horsepower and around £35,000 to the BMW it was a points win for the Smart. Mind you, cars like the Smart can give you a terrible guilty feeling - okay, it lasts only a few seconds - as you realise just how much sense small cars make in the city where size and nippiness are everything.

The Smart Brabus is an extreme example of the marque - its stiffer ride and raucous engine noise can get tiresome. That said, it's great fun up to 40mph and punches well above its weight in terms of hi-tech per pound. At £14,600 it's in a rarefied market, noticeably more costly than the simpler Pulse version at £9,335. That model's a lot more familiar on British roads. In fact, it's rare now to see a LHD imported Smart, proving that Mercedes-Benz is having the last laugh, taking the plunge to import almost the full line up - the most glaring error being the lack of any diesels.

Latest Smarts are literally 'smarter', being over-endowed technologically speaking with more electronic gizmos than you can wave a stick at. It has not dinted the sheer driving enjoyment of the Smart though and the latest revisions make the car that little bit faster, more economical and even safer.

So, I think we can safely establish that city cars are no longer cheap and cheerful alternatives to their bigger brethren. Okay, a few years ago when cars like the Mini, Fiesta, Polo and Renault 5 were chic, the city car brand was limited in the UK to say the least. Well, times have changed - and how! The latest city cars offer more miles - and smiles - per gallon then ever and the city car market is growing in more ways than one.

Take VW's Polo. Launched back in 1976 in the UK it was a genuine city car. The latest version is a far cry from its pert predecessor and is now as big as the original 1974 Golf! Thankfully, not everyone is in the fatuous 'me too' game when it comes to size - and Nissan has opted to take a different route with its latest take on the Micra. For once, the advertising is right, explaining that the latest Micra is a seriously good small car which has kept true to the brand's small car DNA - with a sophisticated new millennium twist.

The original Micra was designed with a five year life expectancy - many motorists in the UK cheerfully proved Nissan wrong and you can still see a few ageing Micras pottering around at the hands of their septuagenarian owners. It was succeeded by the famous blobby shape, which came with a range of excellent engines and the necessary kit and caboodle to make it a favourite with mums and trendy young ladies everywhere.

The latest Micra, launched last year, is the most radical yet; that's not just its styling. Nissan have managed to pack in an amazing amount of technology in a car which is instantly recognisable inside and out and a refreshing alternative to the mainstream opposition from Ford, Vauxhall, Renault, VW and Toyota.

In fact, it's so refined and accomplished it's not really fair to call it a city car - it's a car with no city limits at all as proved in our time behind the wheel. While it's not big, it is clever with big car touches including an intelligent key which unlocks the car for you from a distance, beautifully executed interior and surprise and delight features including a handy storage area under the passenger seat, lovely ivory coloured heating controls and a well integrated interior.

On the road, the 1.2 SX five door (£10,495) is quiet, handles well and offers an undemanding drive, which is typically Micra perhaps but something customers old and new are sure to appreciate. Coming soon is a new, bigger engined diesel version and the icing on the cake: a beautiful looking drop top with a folding hard-top.

Now, what's in a name? For instance what's a Perodua? Exactly! Half the PR battle is establishing the relatively unknown Malaysian brand in the UK. Mind you, you have seen its city car before - in a former life it was the Daihatsu Cuore which has been badge engineered with a shiny chrome grille and alloy wheels to be transformed into the Perodua Kelisa. There are some aspects of the car which are distinctly low rent like the horrible plastic roof lining and dull interior but then we are talking a cheap as chips price with a decent warranty. Its little engine is a good performer and the Kelisa is well made - whether that's enough to convince folk to give it a whirl remains to be seen.

The car sells steadily in a limited market where it slugs it out with the cars like the Fiat Seicento, Suzuki Alto and Daewoo Matiz. For those needing something a little bigger, Perodua have just released the latest version of its Kenari mini MPV, based on the Tardis like Daihatsu Move from five years ago. Our editor will be bringing you his thoughts on that car in the near future.

Roger Blaxall - 23 Jul 2004