THE Lexus NX 300h F Sport auto is unquestionably a technical tour-de-force, but which will leave you scratching your head.

As the pinnacle of performance in this crossover series of two and all wheel drive models, the F Sport is brimming with features to please a "must-have" technophile and lift golf club bragging rights to incredible new heights.

But at the end of the day it is the fuel economy which will bring you down to earth. With a bump.

The problem is that for all its green attributes, its truly impressive specification and the utter sophistication of the way it delivers the performance, the miles it covers between tank refills is poor.

Up front you have a gutsy 2.5-litre four-cylinder petrol engine working with a sizeable electric motor and just to give it all wheel grip there is another small electric motor driving the rear wheels.

It sounds complex but the driver just sits there and pushes down the throttle and the computers take care of the rest.

The power is channeled through a continuously variable transmission for seamless changes as speed rises or falls and it comes with powered rack and pinion steering, disc brakes and this particular car sat on variable dampers set into the front struts and attached to the rear double wishbones. That is serious, purist chassis design and control.

The result is a big car at 1,785kg which handles with great agility and is easy to manoeuvre slowly or quickly. Its grip on the road is good and it has no real vices when taking corners in the country.

Secondary controls are plentiful too and work well with good layout, while the big gauges for speed and engine revs are infront of the driver and separated by a smaller screen showing a variety of selected readouts.

Make a mistake and leave the overall economy showing and you will begin to feel you must be doing something wrong. We struggled to improve on 32mpg and frequently it went just under 31mpg and that was in the most economic mode without setting out to destroy the figure through normal, sport or sport+ modes.

I am inclined to believe the CVT gearbox was partly the reason for the poor consumption.

That said, the Lexus NX300h was a very pleasant environment for any journey, with a high riding position, absolutely sublime adjustable front seats and comfortable roomy rear ones.

Visibility was very good to front and sides thanks to bright lights, big wipers and windows but it was more restricted over the shoulder when pulling out and the test car's rear camera really came into its own.

The car's high spec navigation system was a whopping £2,000 extra, highly detailed and packed with useful information about locations. I was happier with the optional adaptive variable suspension for coping with assorted loads.

That transmission and the kerb-weight probably also explained the modest acceleration and top speed for this executive car.

It looks extremely refined inside and there are lots of oddments places to store things, the dual-zone climate control is highly effective and it's roomy for long journeys with 475 to 1,520 litres bootspace.

But you'd probably feel battered in the wallet at the end of that journey.