While I’m no businessman, if I were, I guess now wouldn’t be the best time to launch a new venture.

With banks tightening up and the public sector shrinking, buying a new car is slipping down most people’s must-do lists.

But Nissan has different ideas. It launched its new upmarket brand Infiniti a year ago, with raised eyebrows all round.

Infiniti is to Nissan what Lexus is to Toyota. Instead of steady-away Micras and co, we have some of the most dashing motors on the road.

It must be especially difficult when you’ve only got one outlet (in Reading, Berkshire), and with a fleet of vehicles, none of which are diesel-powered.

But, against all the odds, Infiniti is succeeding. Never heard of it? Well, these are early days; the brand has been in the UK for less than a year, but the signs are promising. Very promising.

Audis, Mercedes-Benz, Jaguars and Range Rovers are all very good, but they’re pretty common. Just look around well-to-do-areas and those marques are almost two-a-penny.

But Infiniti? Well, it turns heads, as I found out during a day’s driving in leafy Berkshire. Infiniti invited me down to its Reading centre to drive the first range of diesels. You see, even exclusive brands can’t ignore diesel these days.

The company is busy building its UK business. It has already sold hundreds of cars, not all to people in Berkshire, and is establishing a name as a sporty, exclusive brand akin to BMW, where most of its conquest sales come from, and Lexus.

At this point we should give Nissan and Infiniti some credit. Of course, they knew that the recession wouldn’t help, but this is a long-term business and a sticky year or two won’t matter in the long-run.

They knew, too, that dealerships (they call them ‘centres’) needed to be spread around the country, and they are opening in Birmingham and Glasgow, with more on the way next year.

And, of course, diesels are part of the plan. We love diesels in the UK, even though Infiniti’s biggest market, America, is petrol-obsessed.

We now have diesel versions of Infiniti’s two biggest models, the EX sport utility vehicle and its bigger sister, the FX.

With the addition of an M range (think BMW 5 Series and you won’t go far wrong) later this year and some hybrid versions next year, you can see why Infiniti is thinking big.

Tested here is the FX30d Premium. It’s a fabulous car, as you might expect for fifty grand. It matches BMW and co, as you might expect too, but it also has that exclusivity. I imagine that’s important if you’re paying this sort of money.

It’s a sturdy, seductive-looking model which is a crossover between a 4x4 and coupe. On looks alone, it’s alluring, but it’s also incredibly well-equipped and refined.

The EX and FX diesels are powered by a stunningly-smooth 3.0 litre V6 engine which is quiet and responsive.

The EX30d costs £35,975 and the FX30d from £42,761, but the S Premium tested here is £51,730.

It sounds a lot, but they come laden with the sort of kit which rivals charge extra money for, making them actually pretty competitive when compared to a similarly-laden Porsche Cayenne, for example.

In this market, it represents good value.

This version comes with some features which would impress James Bond.

The Infiniti Safety Shield, for example, is a system which keeps you on the right track. If your car starts to wander across lanes, on a motorway for instance, it gently brakes on one side to guide the car back into the lane. Impressive stuff.

Add to that the more standard (but still hi-tech) active torque distribution, collision warning systems and intelligent brake assist, and you have a car which is impressive.

It also has luxury features such as alloy wheels, a 10BG music box, Bose sound system, speed camera warnings and a wonderfully-appointed cabin. It manages 132mph, 0-60mph in 8.3 seconds and an average fuel economy of 31.4mpg. Not bad for a beast of a car.

Despite more engine torque than even Infiniti’s petrol V8, EX30d delivers more miles per gallon and emits less CO2 than the petrol EX models. With the standard seven-speed automatic transmission, CO2 is 224g/km, while economy is 33.2 mpg on the combined cycle from the 235bhp engine.

Infiniti FX30d Premium: PRICE: £51,730.

ENGINE: a 3.0 litre diesel unit with all-wheel-drive generating 238PS.

PERFORMANCE: Top speed 132mph, 0-60mph in 8.3 seconds.

COSTS: Combined route 31.4mpg.

EMISSIONS: 238g/km.

WARRANTY: Three years, 60,000 miles.

Steve’s Ratings: Performance: 4/5 Ride/Handling: 3/5 Space/Practicality: 3/5 Equipment: 4/5 Security/Safety: 4/5 OVERALL: 4/5