Mazda's family SUV has gone to finishing school. The next generation CX-9 due in Australian showrooms in June 2016 is all-new from the ground up and now has some extra polish.

The arrival of the overhauled seven-seater completes Mazda's visual makeover; all its passenger cars now get the company's bold grille and squinty headlights.

Mazda gave media a preview drive of the new CX-9 ahead of the Los Angeles motor show last week.

Rather than driving it on a race track or an autobahn, for once the test route took in the daily grind, to better reflect real-world use.

The two hour test put us in the thick of peak hour freeway traffic and the stop-start snarl of the suburbs.

In fact, it's the same test route engineers embarked on before they started development of the new model.

Mazda studied the typical speeds that family SUVs travelled at on the daily commute and school run.

They drove their test vehicles, equipped with diagnostics to memorise the data, in school pick-up and drop-off traffic, and in the bump and grind of the drive to and from work.

What they discovered surprised them, although it probably would not surprise anyone who endures this task daily.

Family SUVs don't need a high revving engine, their engines barely rev above 3000rpm and the accelerator pedal is rarely pushed to the floor (except for, say, merging onto a freeway or overtaking).

SUVs also need a gentler throttle response. In other words when you push the accelerator pedal, you don't want the gearbox to suddenly shift down a few gears and the engine to flare up, only to hit the brakes moments later.

So Mazda did two things: it developed a brand new engine that delivered most of its torque at low revs, rather than chase power.

The output of 420Nm of torque at low revs is impressive

It also dulled the initial throttle response so the CX-9 is more stress-free in stop-start driving.

Which is why the power number in the brochure for the new CX-9 (169kW if you're curious) may not seem impressive.

But for the geeks among us, the output of 420Nm of torque (car jargon for the grunt that does most of the heavy lifting when moving from rest) at low revs is impressive.

This kind of output is similar to a diesel engine, which brings us neatly to the answer to your next question. No, as with the superseded model, there isn't a diesel CX-9. Instead, Mazda has created a petrol engine with diesel-like qualities and economy. It's genius.

It means the new CX-9 does not have the slight delay in acceleration from rest that is typical of diesel engines. It also means it's quieter and smoother than most diesels.

While the fuel consumption rating is yet to be published, Mazda is promising a 20 per cent reduction compared with the V6 it replaces.

That's right. There's one more surprise. This full-size, seven-seat family SUV is powered by a relatively small 2.5-litre four-cylinder engine -- that's turbocharged, and can run on regular unleaded.

As we would discover, it's no slouch and is more than up to the task.

On the road

Anyone updating from the old CX-9 to the new one will immediately notice the improvements.

The steering isn't as darty as the current model; there are more turns lock to lock so the steering has a much more linear and predictable feel.

The suspension is a touch softer over bumps and lumps, but the CX-9 still feels secure in corners.

It only feels a cumbersome in tight and narrow turns, but that criticism can be made of any vehicle of this size and mass.

Perhaps the biggest improvement is the cabin. The dashboard has a clean and elegant design, one of the best in the business after Mercedes-Benz.

Real timber and real aluminium trim are used as cabin highlights on the top-end models.

The new CX-9 will have five child seat anchor points

All the buttons are well laid out and easy to use but for a couple of exceptions: Mazda's "dial and push" cabin control system could be a little more intuitive, and the optional heads-up display could be supplemented with a digital speed display near the instrument dials.

The seats are snug but the side bolsters don't jab you when you get in or out, and the third-row seats are easier to access because Mazda has lengthened the middle of the body slightly.

Unlike most SUVs in this class, the new CX-9 will have five child seat anchor points -- one in each of the three positions in the second row, and one each for the third-row pews.

It means families can in theory have five child seats fitted at once (if the seats are narrow enough) or fit three child restraints (two in the second row and one in the third row) with room to spare.

Curtain airbag coverage extends to the very last row of seats, but there are still no air-conditioning vents in the last row.

Mazda says cargo space is unchanged (the roof is lower but the cargo bay is wider, to make up the difference).