VOLVO has refreshed its flagship XC90 SUV line-up with new styling upgrades and extra colour choices but the big change is the introduction of mild hybrid technology to the diesel model.

The seven-seat XC90 range, which is priced from £52,235 to £71,945, also sees extended electric driving range for the T8 Twin Engine plug-in hybrid versions - increasing from 21.7 miles to 28.6 miles - which is plenty of scope for an average daily commute.

But the main improvement for the 2020 model, which is on sale now, is the introduction of Volvo's new mild hybrid engine range which is being debuted in the XC90 and called B5.

It combines a 2.0-litre 235hp diesel engine with a 48-volt battery, a kinetic energy recovery system (KERS) and an integrated starter generator.

When the car brakes or decelerates, energy is captured by the KERS system and is stored as electricity in the battery. This is then used to supplement the engine's performance when accelerating and to power the likes of the audio system and lights.

The technology will be introduced to petrol-driven models of the XC90 a little later on.

So, what does all this clever mild hybrid technology mean for day-to-day drivers? Basically it improves fuel efficiency by up to 15 per cent in real world driving and also produces lower NOx emissions than the outgoing D5 XC90 it replaces.

The B5 model is also equipped with an updated automatic gearbox, which improves fuel economy as well as delivering sharper acceleration. And as another first, the B5 breaks new ground by using a brake-by-wire system.

The XC90 is on sale in trim levels called Momentum, R-Design, R-Design Pro, Inscription and Inscription Pro with the B5 mild hybrid engine technology available in all versions.

We tried the Momentum Pro model priced at £56,085 (£59,360 with options). This car could sprint to 62mph from a standstill in 7.6 seconds and maxed out at 137mph, while delivering a combined 37.7-44.1mpg (WLTP) and carbon emissions of 154g/km.

Apart from the additional technology beneath the bonnet, Volvo has given the XC90 a make-over and it features a new grille and lower front bumper, redesigned air intakes, new alloy wheels, plus integrated roof rails and dual integrated tailpipes as standard. Fresh colour choices include Thunder Grey, Pebble Grey and Birch Light.

The car has an impressive list of kit fitted as standard, including the Sensus nine-inch multi-media touchscreen, a navigation system, heated steering wheel, head-up display, front and rear parking sensors, a rear parking camera, two-zone climate control and heated front seats.

Full smartphone connectivity via Apple CarPlay or Android Auto is not a standard fit, but can be added to any XC90 as a £300 retailer fitted accessory or as an upgraded premium sound pack. The latter was an £850 option on our car and introduced a Harmon Kardon system to the mix.

Out on the road, the XC90 B5 handled beautifully and to be perfectly honest, the new mild hybrid technology was not noticeable, which is a credit to the engineers as it has slipped seamlessly into the smooth running of the car.

The acceleration was crisp and sharp with ample power on tap for quick bursts of speed when overtaking. The cabin is beautifully hushed against any engine, road surface or wind noise and the car's highly efficient suspension system does a worthy job of smoothing out any uneven surfaces along the way.

There are drive modes called Eco, Comfort, Individual, Dynamic and Off Road that alter the way the car reacts and its always worth remembering that the XC90 has all-wheel drive to keep you moving in more adverse weather and driving conditions.

Comfort levels are sublime with soft Nappa leather upholstery giving the cabin a truly premium feel. And being a fully scaled SUV the XC90 can accommodate seven occupants and features a wealth of storage options.

The boot capacity ranges from 314 litres with all seven seats in use to a whopping 1,868 litres with rows two and three folded flat and there are lots of compartments to hide away goodies throughout the car.

Volvo has a well established reputation for developing very safe cars and the XC90 is further proof of that know-how. It secured a maximum five stars when it was tested for its Euro NCAP safety rating and boasts a whole host of driver assistance aids and safety equipment.

Volvo is riding on the crest of wave at the moment and despite the general downturn in car sales, it is bucking that trend and recorded outstanding global sales figures last year of 600,000-plus units - more than 50,000 of which were in the UK.

And in the first six months of 2019 alone, more than 30,000 sales have been clocked up in the UK, so it looks like being another bumper year for the Swedish giant.