THIS latest Mazda3 is a game-changer, easily matching its two main rivals and - dare I say it - quite possibly the best in class.

Whether pressing on along some of the best driving roads in Britain, or tackling a 20-mile stretch of demanding single-track road, the Mazda3 remained composed, planted and hugely enjoyable to drive.

First impressions are excellent. On the outside there's a visual link with Mazda's 6 and CX-5. Curvy, low slung and sleek, there's really nothing to dislike and plenty to admire.

Step inside and you instantly feel at home and at ease. It's a distinctly Japanese cabin and the detailing is smart, without trying too hard. And then you come across some new tricks.

Mazda has included an infotainment system on mid-range trims and above, with two USB ports, a 3.5mm port, Bluetooth and an SD card slot, although the latter is occupied by the navigation system's maps data.

The advanced connectivity system integrates online social media and internet radio using Aha, the cloud-based automotive internet connectivity platform, and Stitcher, the on-demand internet radio service app.

Using a smartphone connected to the system via Bluetooth, occupants will have safe and intuitive real-time access to infotainment services from Aha and Stitcher via the seven-inch dash-top display.

Rear legroom is ample (I'm a six-footer and my knees were clear of the driver's seat), and shoulder room has been increased. Although the Cpillars are broad, sitting in the back doesn't feel claustrophobic.

With a price range of between £16,695 and £23,345, buyers can choose between five equipment levels - SE, SE Nav, SE-L, SE-L Nav and Sport Nav. But even the entry-level model comes with a generous amount of equipment, including smart city brake support, secondary collision reduction, alloy wheels, air conditioning, seven-inch colour touch screen, USB/iPod connectivity and Bluetooth hands-free system as standard.

Head for the top of the range with a leather interior and electronic seat adjustment and you are within a gnat's whisker of premium class.

Yo u even get a head-up windscreen display on Sport models.

There's a 36-strong line-up of models to choose from - 21 hatchback and 15 fastback (saloon) - and this vast choice is bound to lead to plenty of umming and ahhing in the dealer showroom.

I tried out the sole diesel option - a 2.2-litre unit with 148bhp - and both manual and automatic hatchback versions of the 2.0-litre powerplant with 165PS. There's a third petrol option - a 1.5-litre unit producing 100PS.

Yo u might have spotted that the diesel offering makes it up to 600cc larger than the most popular diesels on sale today, but it emits only 107g/km of CO2. The saloon version is rated at just 104g/km.

Downsizing isn't the right way forward, says Mazda: this is what it calls 'right-sizing' through its Skyactiv suite of technologies.

Rather than shrinking and turbocharging its engines, Mazda has retained capacity but employed technology that makes the parts lighter and more efficient and brings better fuel economy.

The achievement is astonishing.

The torquey SkyActiv-D twin-turbodiesel, despite its capacity, is so clean it passes Euro 6 emissions regulations without any need for additives.

On the road, it's superb. Quiet and smooth. it is armed with turbochargers that reduce lag and bring bags of torque to the party.

Despite the diesel's strong performance, the petrol variants are likely to account for the majority of retail sales. Refined and quiet, with real clout in the higher-powered versions, it is a joy to drive.

Whichever you opt for, the brilliant drivetrain, excellent handling, a compliant chassis, stiff body and just-right suspension make this a most impressive car.

Mazda sales in the UK were up 53 per cent in November compared with the same month last year and up 18 per cent on the year to date.

The Mazda3 should ensure a flying start to 2014.


Mazda3 2.0 Sport Nav

Price: £19,895 (range from £16,995)
Engine: 2.0-litre petrol producing 120PS
Transmission: six-speed manual gearbox driving the front wheels
Performance: top speed 121mph, 0-62mph in 8.9 seconds
Economy: 55.4mpg
CO2 emissions: 119g/km