The verdict: This week, readers have a spiritual experience testing the Audi A4. By Michael Booth.
Well, here's a first: a diesel I can happily recommend for reasons other than economy. That's not to say the new Audi A4 2.5 V6 TDi isn't frugal. Indeed, it can eke out over 40mpg. It's just that, for the domestic user, frugality is rarely enough to warrant the extra cost of purchase, the unsociable - and carcinogenic - black exhaust emissions and an engine noise like a child running a metal ruler along a wooden fence. To compete in the executive saloon market, a diesel must offer more than just fewer visits to the pumps.

And this one does. The A4 TDi is a great car, not just a great diesel-engined car. Having said that, when I took delivery of the A4, I wasn't exactly hyperventilating with excitement. Audis have always exuded a discreet elegance, but their passionless anonymity appears to attract an older, frankly "nicer", demographic than their rivals (I've always thought that Audis were BMWs for people with morals; I reckon God would drive one if he wasn't omnipresent and didn't need transport).

After a few miles ensconced in the A4's understated but opulent interior (think Bang & Olufsen stereo), I had become an Audi convert, and had revised my opinion of diesels, too. The inevitable turbo lag aside (which means that acceleration, when it comes, is perhaps more of a surprise than you'd like), this is an extremely quick car, particularly above 60mph. Whether you believe the democratisation of supercar performance in family saloons is a good thing in road-safety terms or not, the A4 is a riot, the sort of car that, with its reassuring ABS and traction control, you drive just for the pleasure of soaring past everything else on the road.

Complaints? Well, as much as they've tried to hide it, the engine still sounds a touch bronchial when cold - the noise becomes a sporty growl at speed - and its cousin, the VW Passat TDi, is pounds 6,000 cheaper (the Audi has a list price of pounds 24,944). In our car, with the air-conditioning blowing hot air on to the windscreen there was an accompanying smell of meat pies. What's more, the boot opening isn't big enough, neither is the rear leg room, and without sounding churlish, working your way through six gears (which you need to do because this car is unusually sensitive to a sloppy choice of ratio), can be tedious. But none of those things would remotely put me off the A4 diesel if I was in the market for a car of this size and covered more than 20,000 miles a year

Road test If you would like to take part in a test drive, write to The Verdict, The Independent Magazine, One Canada Square, Canary Wharf, London E14 5DL, giving a contact phone number, your address and details of the type of vehicle, if any, you currently drive. Participants must be over 26 for most vehicles and have a clean driving licence.

Robert Murray: 63, from Harrow, Middlesex, retired electronics engineer for Kodak. Currently drives an Audi Coupe

Robert is a committed Audi fan. "They're brilliant," he says. "So reliable. You know an Audi from the way the doors close and the seats hold you. It just shouts quality. And this is the diesel I've been waiting for, it fulfils the main criteria, which is that the boot can take four sets of golf clubs." On the move, Robert was equally impressed: "You get plenty of feel, the steering lets you know what's happening up front, it's nice and responsive." Slight gripes included the stingy rear leg room and the fact that DIY maintenance was no longer an option. "You couldn't work on this without a computer."

Virginia Curry: 43, from Richmond, Surrey, magistrate, part-time parish administrator, mother and housewife. Pictures with children Andrew, nine, and Alison, 11. Currently drives a Saab 9000

"I don't like the lines of the Audi. You feel you're sitting in a bucket, because it has a very high waist line. It's also not as roomy as my Saab, but it's definitely a quality car." Gripes included the lack of cruise control, "wonderful for foxing speed cameras", and the fact that diesels were no longer perceived as environmentally friendly. "And cigarette lighters are so dangerous with children around. I don't know why they still put them in the dash." Alison observed the doors made a nice clunking sound and Andrew liked the indicator click.

Chris Austin: 35, from Streatham, London, sports development officer for Wandsworth Borough Council. Currently drives a Ford Sierra

"The Audis I usually see are rickety old crates, but I like this one," was Chris's first impression, although, with the engine running, he could tell immediately that this was a diesel. "It's nowhere near as noisy as my Sierra, though, and that's not even a diesel, and it's much lighter to drive and very pleasing on the eye." Criticisms included the narrow boot aperture, and a lack of BMW-style street cred and personality. "The name Audi doesn't mean a great deal to me, to be honest. It's all very functional and does everything it should, but not in an outstanding way."

David Walford: 57, from Plumstead, London, retired hotel manager. Currently drives a Suzuki Swift

Reliability is the word David thinks of first with Audi, but he felt ours was let down by details: "It's a bit plasticky for the money, you need a bit of wood on the dash, it always adds a touch of class." David had no problem with diesel power in such a prestige motor: "It doesn't sound like a diesel." But he did find the car lacked power if you were in the wrong gear. "And I always think six gears are too many, why can't people be happy with four?" David found the interior well laid out and liked the power steering. He was irritated, however, to find his head banged on the top of the door seal with the seat on a high setting and thought a sunroof should be standard for pounds 25,000.