JUST how much space can a family really need in the boot of their car? Are they so hopeless at packing that there's simply never enough room to squeeze everything in?

It's a pertinent question after you've glanced under the boot lid of the new Mazda6 saloon, to discover a black hole that seems to stretch forward, almost to infinity.

And then you pull up the tailgate of its (surprisingly, shorter) estate sibling and discover that with the rear seats flopped forward there's space to move a modest apartment without needing a return journey.

More extraordinary still, is the discovery that this handsome Mazda, called a Tourer in estate guise, is by no means as spacious in the extreme rear as you'll find in its class.

A Ford Mondeo and VW Passat both edge a maxed-out Mazda on luggage space and the Skoda Superb gallops off into the distance clutching the 'I'm much bigger than you' challenge trophy, thrashing all of them out of sight.

But let's suppose the Mazda6 Tourer is big enough for you and your family (which it almost certainly is); what is there to appeal about the rest of the car?

Well, take the looks. There can't be a car in its class that blends such sharply flowing lines into a shape that still manages to wrap itself around something that's simply got to be practical in everyday life.

Then there's the clever technology Mazda brings to the party, fitting a diesel engine (which will take many more sales than the petrol model) that bucks the trend for downsizing yet still manages excellent economy.

Employing something called SKYACTIV technology, it uses the lowest compression ratio of any diesel on the market and that results in a lighter engine and one that meets stringent new pollution levels without really trying.

Even if that last paragraph made as much sense to you as a teach-in on quantum mechanics, you may still be impressed with the 52mpg the car here showed on its commendably legible trip computer after more than 500 miles on test.

Add in an engine that never intruded, not even from a cold start when diesels can be raucous, and pulled like a runaway train when provoked, and Mazda's new tech works a treat.

There's nothing very high tech about the living environment inside the Mazda6, and that's meant as praise. It's too easy to let the designers run free and produce something that looks smart in the brochure but will be a pain in the neck as the months roll past.

Not so here, with lots of solid, sensible blackness in plastic and leather and a set of dials and switches that could hardly be easier to use. Mazda has stuck to its practical guns for years now and good for them, says I.

The diesel Mazda6 Tourer price range starts at £22,795, for a car more than adequately adorned with fittings, from alloy wheels, air conditioning, trip computer, colour touch screen and cruise control.

The car I tried sits near the other end of the range and comes dripping with kit. Highlights include a boomy Bose sound system, full leather trim, heated front seats, with powered adjustments for the driver.