HOW long will before the Q-series SUVs overtake sales of Audi’s traditional saloons? Audi has sold more than 400,000 Q5s worldwide since 2008 and its mid-size SUV is snapping at the heels of the A4.

Over the past ten years, the Ingolstadt-based carmaker has almost doubled its annual sales in the UK and a significant chunk of that growth can be put down to the popularity of the group’s SUVs.

The same story has been repeated all over the world. In the US, sales of the Q5 increased by 35 per cent in the first six months of 2013, helping the marque to a record-breaking market share; in China the Q cars are so popular Audi has built a dedicated factory just to satisfy demand.

It seems almost inconceivable now to think that the first Audi SUV (the Q7) was seen as something of a gamble by the company.

Since then, we’ve had the Q5 and the Q3. Still to come is the baby of the family - the Q1 - which is due in 2016.

Of all the Audi SUVs, the Q5 has the toughest job because it competes in the mid-sized premium segment,where desirable cars such as the Range Rover Evoque and the BMW X3 are the major competition. To keep the Q5 competitive, Audi has instituted an aggressive upgrade programme for its best-seller.

ON THE ROAD: ​The range of improvements made to the Q3 for the 2014 model year are the most extensive so far. So wide-ranging, in fact, that Audi bosses insist this is a whole new generation of Q5.

Not that you’d guess from the outside. The Q5 remains stubbornly a Q5. Audi broke new ground for an SUV with the Q-Series, eschewing the boxy look for rounded curves and flared wheel arches. The latest Q5 stays true to its heritage any changes are subtle, to say the least.

The enormous front grille has rounded corners, the front bumper has a new profile and the headlights are different, but to be certain you’d still need to park a 2012 Q5 next to a 2014 model.

The big news is to be found beneath the bulbous bonnet where there are three new engine choices: a next gen 2.0-litre TDI, a 225 bhp 2.0 turbo and a supercharged V6. Naturally, its the entry point 2.0 diesel that’s set to become the best-seller. Packing 177 bhp and 380 Nm of torque, it slices a full second off the old TDI’s 0-62 mph time and still returns a combined fuel consumption figure of 47.9 mpg.

Thanks to the rounded body the Q5 posts the best set of aero figures in its class. On the German autobahn the slippery shape helps the 2.0 TDI reach an impressive 127 mph top speed, considerably faster than the e4D Evoque (which can only manage 112 mph).

Softer springs make the ride more comfortable than ever and the electro-mechanical steering has a touch more heft. On the go, the Q5 responds quickly to inputs and absorbs the worst our roads can throw at it. The gearbox has that precise, well-machined feel that’s a VW staple these days and the brakes have the typical over-servoed response which requires a degree of caution until you’re used to them.

The new TDI is more refined than its predecessor and much smoother, particularly in the upper rev range.

​ ON THE INSIDE: ​ Audi has turned automotive cabin design into an artform. The Q5 is no exception. For 2014 more of the controls are trimmed in chrome and the centre console panels are finished in trendy high-glossy black. The ignition key is new and the instrument needles are supposed to be clearer. As you’d expect of a premium model, the fascia is lovely to look at and all the touch surfaces are a tactile delight.

The cabin has room for five adults but a third passenger in the rear will have a hard time thanks to the chunky transmission tunnel. In the front, the tunnel adds a cosy appeal to the accommodation and creats a cock-pit feel.

Audi’s updated multi-media interface (MMI) scatters the audio controls across the transmission tunnel. This year, in the interests of clarity there are fewer knobs to twiddle and you’ll soon get used to turning the volume up by turning a knurled dial near your left thigh. Materials, colours and upholstery fabrics have also been updated – there are three new interior colours, three fabric and three leather qualities and a total of 35 different combinations offering plenty of scope for personalisation.

The Northern Echo:

​ WHAT DO YOU GET: ​ There’s no cheapie two-wheel drive version in the Q5 line-up. Quattro four-wheel drive is standard across the range. Three trim levels are available in the UK – SE, S line and S line plus. Standard kit includes alloy wheels, which vary in size from 18 inches to 20 inches, leather upholstery, electronic climate control, the Driver’s Information System with efficiency function and a new rest recommendation feature (which tells you to take a break when it detects erratic driving inputs), the MMI linked to a 6.5-inch colour monitor, rear parking radar, light and rain sensors, a hill descent assist function and split/folding rear seats.

It’s a shame the standard Audi warranty only lasts for 60,000 miles or three years when rivals offer unlimited mileage cover over the same period.

HOW PRACTICAL IS IT? ​ The 540 litre boot is smaller than an Evoque (575 litres) and an X3 (550 litres). With the seats folded the Audi claws back some practicality to overhaul the Range Rover (1560 litres vs 1445 litres) but still plays second fiddle to the Beemer which has the biggest carrying capacity of these three rivals at 1600 litres.

The 2.0 TDi has a 2000kg braked towing weight which is better than the Range Rover and the same as the BMW.

The Northern Echo:

​ RUNNING COSTS: ​ Audi claims the 2.0 TDI returns 47.9 mpg on the combined cycle. BMW claims 50.4 mpg for the X3 and the Evoque is a real fuel misery with a 56.5 mpg return. As ever, your real life returns will depend on how - and where - you drive. Surprisingly, the Q5’s slippery aerodynamics don’t hand it a green advantage. The Q5’s exhaust emissions are worse than the BMW (149g/km) and the Range Rover (133g/km).

​ VERDICT: ​ ​It’s easy to see why the Q5 has been such a hit. It’s beautifully built, handsome in an understated way and pleasant to drive. It has the commanding seating position drivers love, the badge cachet you get with owning an Audi and should hold its value very well.

AUDI Q5 2.0 TDI.

Price: £32,220 Spec:​ Engine: ​2.0-litre turbodiesel/4 cylinder Power: ​177 bhp @ 4,200 rpm Torque: ​280 lb/ft @ 1750-2500 rpm Top speed: ​127 mph 0-62mph: ​9 seconds Fuel economy: ​47.9 mpg CO2 emissions: ​154 g/km ​Equipment: ​ Alloy wheels, rear parking sensor, 6.5-inch colour monitor screen, electric windows (4), power steering, four-wheel drive.

​ ​ ALTERNATIVES:​ ​Range Rover Evoque: 2.0 diesel not as powerful as the Q5 but the Range Rover looks fabulous BMW X3: Nice to drive and great 2.0 TDI engine but everyone will ask why you didn’t buy an X5.