What on earth has the Hindustan Motor Corporation's R&D department been doing for the last 25 years?

The Hindustan Ambassador is unashamedly a Morris Oxford - but the models imported to Britain have 1.8-litre Isuzu engines

The Research and Development department of the Hindustan Motor Corporation, Calcutta, employs no fewer than 250 people. Quite what they have been doing over the past 25 years is anyone's guess. Today's Hindustan Ambassador saloon is precious little different from the Hindustan Ambassador of 1971. Or 1961.

In fact, the Ambassador is a 1954 Morris Oxford, and unashamedly so. The Churchill-era Oxford was never the raciest of cars: as stodgy as porridge made with powdered milk, it was replaced in the MacMillan years (1958) by an altogether sharper model styled by Pininfarina, the fashionable Italian "carozzerie".

Even so, the veteran Ambassador remains one of the most popular "old buses" (ie cars) in India and, according to Mark Owen-Lloyd (who imports the old girl to Britain), the only Indian-made car that refuses to fall to bits on the hot and dusty roads of the sub-continent.

Now, if an Ambassador can cope with the Khyber Pass, it must surely be a match for the pot-holed by-passes of old England. Owen-Lloyd thinks so. So does Jo Burge, his partner at Fullbore Motors, Fulham, London. The two met at Oxford. A combined passion for classic cars and India took them to the Hindustan factory in Calcutta.

If, reasoned Burge and Owen-Lloyd, people back home were prepared to pay up to pounds 14,000 for a reconditioned Morris Minor, surely they could be persuaded to part with pounds 7,750 for a much bigger and more distinctive Ambassador?

The first cars arrived, factory-fresh, in Fulham in 1993. To date 78 Ambassadors have rumbled out of Heathmans Yard (Fullbore's headquarters) on to Britain's roads. This year the company plans to sell six cars a month.

This modest target should be within easy reach, for although it is easy to sneer at the idea of spending the best part of pounds 8,000 on a roly-poly old Morris made on the banks of the Ganges, the Ambassador is great fun, extremely good value and makes friends like few other cars this side of a Mk2 Jaguar.

Finished in gloriously Fifties-style red, blue, green, ivory or black (two-tone paintwork is available on request), the Ambassador is the automotive equivalent of a High Church, C of E vicar: dignified, upright, staunchly conservative. It goes well because the chaps at Fullbore have replaced the Ambassador's original engine (the venerable BMC B-series 1.5-litre jobbie) with an 86bhp, 1.8-litre engine designed by Isuzu for oriental delivery vans. The advantage of Japanese automotive power is that the car starts at the touch a of Bakelite button, refuses to overheat or breakdown and runs for 12,000 miles (or 12 months) between services, which cost around pounds 100 a shot.

Smooth and powerful at low revs, the Isuzu motor allows the Ambassador to cruise happily at 80mph at under 3,000rpm in fifth gear on motorways and, should you be brave enough, to top an astonishing 110mph. The big drum-brakes pull the car up fairly and squarely. It returns 30-35mpg (lead- free) in normal use.

A few tweaks to the car's suspension stop the Ambassador from rolling around corners like a Ganges ferry in a monsoon (as Indian models do), while thick leather cushions and soft springs make for a ride fit for a maharajah. You will never be tempted to enter this car for a traffic- light grand-prix, but it bowls along serenely, wind whistling gently from the chrome-plated quarter-lights and the heater doing its level best to transform the biting chill of London into the soothing torpor of Mysore.

Fresh from the factory, the Ambassador comes with a set of decidedly low-caste plastic switches and dials. These can be replaced by Fullbore's offer (at extra cost) of a wood-veneer dashboard and other pukka fittings. Complete with leather seats, pullman headlining and thick carpets, the Ambassador makes a handsome town carriage.

Not everyone thinks so. I took an Ambassador for a drive along Brick Lane, Spitalfields - heart of east London's Bengali community. Parked outside the Clifton restaurant, the Ambassador soon drew a small crowd. It illicited these comments:

"You bought this?" (incredulity);"I'd prefer a Nissan, or even better a Mercedes."

"My father drives one in Calcutta - he's a taxi driver."

But, is it (I had to know from those in the know) a "good old bus"?

"Yes", said a young waiter. "Like the Number 8." Guffaws all round.

I drove to Catford (home of mechanical dogs and more second-hand car dealers than Arthur Daley could count in a month of free-trading Sundays). I bumped into a local car-boot sale (metaphorically, you understand; the Ambassador's big drum brakes are well up to the job of stopping this 30cwt juggernaut).

"Lovely motor" said a man in a Tam o' Shanter, selling socket sets.

"Very practical, I should think", said the man next to him. "Myself, I drive a 1981 Lada; wouldn't mind what you're driving."

"I'd definitely trade in my MkIV Tina for one", said a third, earning a crust from pine toilet-roll fittings.

My own preference would be a for a second-hand Jag for much the same money, But, where the Jag would cost a bob or two to keep in plugs and points, the Ambassador will run and run for servicing costs of no more than pounds 150-200 a year. And you can rest assured that parts will be available for years; the chaps in Calcutta have toyed with a bigger back window, but they are unlikely to be busy with radical new plans for the Ambassador as this Hindu Morris chugs into the next millennium.

Fullbore Motors 0171-371 5931