THE Volvo XC90 is the Swedish car maker's flagship model and the original version of it helped to redefine and reinvigorate the brand some years back.

Since then Volvo has been on a steep upward trajectory and the evolution of the XC90 is testament to that.

The latest revisions to the second generation XC90 have seen the arrival of two mild hybrid turbocharged versions - both petrol and diesel.

The diesel came first and was followed more recently by a petrol option.

Somewhat confusingly both are known as B5, deviating from Volvo's naming convention of T for petrol power and D for diesel power.

Both feature 2.0-litre units under the bonnet and both offer reduced emissions and improved economy.

It means that the XC90 range now offers these petrol and diesel mild hybrid options, along with a supercharged 2.0-litre petrol model - the T6. There is also as a plug-in hybrid - the T8.

Both B5's combine internal combustion engines with an electric motor. The motor assists the engine and brings multiple benefits, boosting performance improving economy and lowering emissions.

As with most modern mild hybrids the two power sources combine seamlessly.

Given that most XC90 buyers have traditionally tended to plump for diesel over petrol it's likely that the 235bhp diesel B5 will prove the bigger seller over the 250bhp petrol, though with the petrol/diesel balance having shifted somewhat over recent years and continuing to do so perhaps time will tell on that score.

They share the same drivetrain set-up utilising a 48-volt battery, a KERS (kinetic energy recovery) system and an ‘ISG' integrated starter-generator.

It means every time the driver brakes or takes their foot off the accelerator, surplus energy is captured and stored as electricity in the battery, which is located in the boot.

In turn that additional electricity can be used to boost acceleration, help the stop/start system or power other functions.

The aim is to deliver overall efficiency rather than pure electric motoring and this is also achieved in tandem with revisions to the automatic gearbox and a new brake-by-wire system.

The XC90 had a makeover in 2019 and still looks remarkably fresh, continuing to be a strong contender in its segment, where it's up against vehicles like the Audi Q7, BMW X5 and Land Rover Discovery.

It's seven-seat capacity and ingenious interior storage solutions strengthen its offering considerably.

Entertainment and connectivity are other strengths - Volvo's tablet-style touchscreen is wonderfully intuitive and easy to use.

Of course safety - a long-standing Volvo trademark - has not been neglected either.

Features include City Safety - which warns of a possible impending collision with a pedestrian, cyclist or large animal and brakes the car if you don't react, Oncoming Lane Mitigation to automatically bring you back into your lane if you drift and Cross traffic Alert which warns you of moving cars as you back out of parking spaces.

The latest XC90 is bigger than the original version but feels surprisingly nimble and easy to for a large vehicle - even in an urban setting.

A wonderfully refined ride and surprisingly sharp handling for a high-riding SUV also combine to ensure the XC90 offers a thoroughly decent drive overall.

The driving experience can also be tailored using the various drive modes - eco, comfort and dynamic.