Given an unlimited budget to buy and run a luxury 4x4, most people’s eyes would instantly turn to the thunderous petrol versions.

But prohibitive expense put these out of reach and it’s possible to get most of the enjoyment a lot more cheaply with a good, solid diesel.

Say hello to the Infiniti FX30d.

Infiniti is looking to offer customers a lot for their money with the FX luxury 4x4. That’s in terms of equipment, performance, handling and customer service. The FX30d model is a perfect fit with this policy, with its diesel engine bringing running costs down to a more accessible level.

Infiniti still won’t be a familiar name to many in the UK and it certainly isn’t one that most people would automatically group together with the likes of BMW, Audi, Mercedes-Benz and Lexus.

And these premium car brands just happen to be exactly where Infiniti has positioned its crosshairs.

Infiniti is the luxury car arm of Japanese manufacturer Nissan. It’s no surprise then that the diesel engine installed in the FX30d is a modified version of the 3.0 V6 unit that’s found in a number of larger models from Nissan and its alliance partner Renault.

Its power output of 235bhp makes it one of the strongest V6 units with a single turbocharger and maximum torque of 550Nm at 1,750rpm virtually guarantees plenty of shove through the heart of the rev-range. The engine is matched to a seven-speed automatic gearbox that can zip through the gears and see the FX30d to 60mph in 8.3s.

The Infiniti is a full size luxury 4x4 with a focus that’s very much on comfort and performance on the road rather than tackling difficult off-road terrain. There’s a lot of technology under the skin of the FX designed to enhance its road-going performance. The intelligent all-wheel-drive system distributes torque automatically to the wheels where it can be put to the best use and the stability control software is on hand to rein in any excesses on the driver’s part.

Buyers wanting an even sportier feel can upgrade to the FX30dS model. This has the same engine but adds sports suspension with electronically controlled dampers that react to the road conditions and active rear wheel steering which turns the back wheels as well as the front to improve manoeuvrability at low speeds and stability on the open road.

With its elongated shape and small glass area, the FX has the look of a coupe on stilts rather than a conventional large 4x4. There are obvious similarities in the basic styling approach to the BMW X6 but the detailing is very different with the FX displaying curves and bulges in place of the BMW’s sharp, angular lines. The long bonnet, steeply raked windscreen and vents behind the front wheel arches contribute to the sporty appearance. In the metal though, the car’s sheer size means it still has the imposing presence of a 4x4.

The links between Nissan and Infiniti are only really evident in the cabin with elements of the design and switchgear adapted from previous Nissan products.

Huge efforts have also been made to generate the premium feel that’s so important in the luxury 4x4 segment.

Infiniti is making great play of the equipment levels offered as standard.

You can inflate the price of rival models far above that advertised with a few choice extras from the options list but the Japanese brand is banking on low prices and a comprehensive standard specification giving it the edge it needs. There are GT and S models on offer, both upgradable to Premium status by which point virtually the entire options list is thrown in.

FX GT customers get Bi-Xenon adaptive headlights that turn with the steering wheel, full leather trim, heated and cooled front seats with electric adjustment, I-Key smart access, cruise control, electric sunroof, 2Gb music jukebox, rear view camera and cruise control.

The S models add powered sports seats, vast 21-inch alloy wheels, Rear wheel Active Steering and Continuous Damping Control. Go for the Premium models and there’s Intelligent Cruise Control which can maintain a set distance to the car in front and Intelligent Brake Assist which can warn of a potential collision and brake the car if necessary. At this level, there’s also the Connectiviti+ package which combines a DVD player, satellite navigation, a 10Gb music jukebox and a Bose premium stereo with 11 speakers.

On the road the FX30d returns 31.4mpg on the combined cycle with emissions of 238g/km. A key determining factor for overall running costs will be the residual values and Infiniti is confident that these will be strong thanks to the controlled supply and high specification of the FX.