VOLVO may not think the diesel engine has much of a long term future but the maker of Scandi-style upmarket family transport hasn't waved farewell to the smelly pumps just yet.

For the next three years at least - or until the big XC90 range is comprehensively replaced - you can buy one of these spacious seven seaters with a diesel under the bonnet - but now backed up modestly with battery power too.

It's part of a pledge to give the entire Volvo range some form of electrical propulsion, ranging from a mild hybrid (without the ability to plug into the mains), a full hybrid that takes a charging cable or a full-on all-electric car that relies on amps alone.

The latest XC90 is a mild hybrid, using a revised starter motor to gently assist the 232bhp 2.0 litre diesel move the car from rest or help at a gentle cruise, all in the line of improving economy and emissions.

The electrical energy is generated as you brake or step off the throttle and is stored in a small secondary 48 volt battery. Volvo says this new B5 version improves real life economy by up to 15 per cent and cuts the NOx emissions that get diesel critics hot under the collar.

Under the new and more real world WLTP testing the XC90 B5 diesel recorded an average between 37.7 and 44.1mpg, depending on the size of wheels fitted, and 156g/km of CO2.

The B5 also gets an updated eight-speed automatic transmission aimed at improving efficiency and smoothing gearchanges as well as sharpening acceleration from standstill; top speed is 137mph with 0-62mph taking 7.6 seconds.

Prices of the latest XC90 range start at £52,235 for a Momentum grade car with petrol engine and all-wheel drive and top out with the £71,945 Inscription Pro T8 that combines a potent petrol powerplant with plug-in recharged electric motor to award itself a Twin Engine moniker.

Pick the new B5 mild-hybrid and prices range from £53,285 for a Momentum grade to £61,885 for the Inscription Pro with R-Design versions in between.

Whichever new XC90 takes your fancy, the third biggest seller in Volvo's UK range now comes with a very mild mid-term facelift that takes in gentle revisions to grille, air intakes and front bumper along with new alloy wheel designs.

Every XC90 also now comes with integrated roof rails and twin exhausts as standard, while R-Design variants have a gloss black finish on parts like door mirror casings and window frames.

The interior is untouched except for an additional choice of slate upholstery colour in addition to the current charcoal.

Half of Volvo sales are diesels at the moment but they're on a gentle decline (like the rest of the car industry). In the case of the company's biggest SUV this form of propulsion will be on offer until the next full model change, probably in three years or so.

And for company car users it continues to make sound financial sense to put diesel in the tank. Drive one of the new B5s and it makes sound sense on the road too.

Pulling away from rest you'll note a distant diesel rasp, but it's gone by the time you approach a cruise and never intrudes at any speed. Sitting up high you lord it over lesser machines without the perceived arrogance that seems to attach to some rival makes - a lasting legacy of the brand's Swedish heritage, perhaps?

On narrowish Cotswolds' lanes for the first drive of the newcomer, you're keenly aware of the XC90's generous girth and with more than 2.1 tonnes to haul about, that new engine combo has some work to do.

With optional (and £1,000 extra) 22-inch alloy wheels helping the looks but not the economy, a trip readout of 35.6mpg looked a decent return for the work behind the upgrade.

Driving a non-hybrid diesel on the original launch some years ago saw 34.0mpg on the dash - so it's modest but useful progress.

Otherwise, the XC90 remains the well equipped, handsome people mover it always was. But now a bit more eco friendly.