SPACE may have been the final frontier in those original Star Trek series of the 1960s, but when it comes to new cars the sky is still very much the limit.

Take the Citroen C4 SpaceTourer, which comes in both standard variant with five seats and supersize Grand - with five or seven seats - as a case in point.

This is the model we once knew as the C4 Picasso, now with a new name that hints at exactly what buyers can expect, along with a bright new style.

The result is a vehicle that ticks just about ever box a family on the move could hope for - at a price most will find a way of affording.

To be successful in this fiercely competitive area of the market a motor manufacturer needs to offer something different, something compelling and, hopefully, something the rest haven't identified.

The C4 SpaceTourer, and Grand variant in particular, does just that - principally from the inside.

An ideal starting point is with the windscreen. It's huge, and if you slide back the sun visors it opens up an even bigger glass area that makes sitting up front feel more being in a bubble than a cabin.

And the vast panoramic glass sunroof ensures that the view from every position in the car is fabulous.

Many seven-seaters can prove cramped, but the design of the longer wheelbase Grand SpaceTourer is such that the middle row of three individual seats slide separately and even when fully slid back - which provides a huge degree of legroom - there's still a substantial boot area.

Keep the third row in place and there's sufficient comfort, as we discovered on a trip to the Lake District, for a 17-year-old to travel 80 miles stress-free.

As for space, the 632 litres available expands to 793 when you fold the rear seats down and, having hands-free operation, you can open the tailgate automatically by moving your foot under a sensor on the bumper.

Other smart touches include flip-down trays on the front seat backs, that have cup-holders and their own push-button lights, while there are also magazine nets and controls for altering ventilation levels for the outer second row seats.

An auto gearshift lever mounted above the steering wheel may seem a bit quirky but it works well and combined with the use of an electronic parking brake it opens up plenty of extra space for drinks holders and a deep two-level central storage box with sliding cover.

And a double screen in the centre of the dash means that all the digital info is easily accessed so that the driver doesn't have to peer through the steering wheel to check speed or fuel levels.

Both PureTech petrol and BlueHDi diesel engines are up for grabs, though anyone fearing the 1.2-litre three-cylinder could be underpowered for a substantial seven-seat vehicle is in for a surprise.

Not only did we average 44.7 miles per gallon over 250 miles of mixed urban and motorway driving but the SpaceTourer was comfortable, engaging and punched above its weight.