After years of engine downsizing, BMW's decision to replace its four-cylinder X5 40e with an inline six-powered 45e is welcome news. Not just because this is now a hybrid with a more powerful, sweeter-sounding motor, but because it also offers greater fuel economy, extended electric range and lower CO2, thanks to accompanying improvements in battery technology. It also means that for the first time, BMW's hybrid X5 mixes genuine driver appeal with broader efficiency claims - which immediately feels like a winning combination.
The 45e's powertrain is shared with the 745e, so it combines a 285hp 3.0-litre inline six with an 81kW electric motor that delivers an additional 112hp directly into the eight-speed torque converter. Combined, it outputs 394hp and, more interestingly, 442lb ft of torque - which, coincidentally, is exactly the same amount of twist produced by the highly-strung six-pot in the F80 M3 CS. Admittedly, the X5 45e is rather portly at 2.4 tonnes (300kg of which are batteries), but with instantaneous electric shove its rolling performance out to be really rather good. And comparable with Volvo's arch-rivalling XC90 T8 Twin Engine.
Our test car wore M Sport trim, so while it boasts plenty of eco credentials, the model possesses enough visual clout to appeal to British tastes. If there's a trim level to somewhat dilute the impact of those ever-divisive front grilles, it's M Sport, because the addenda - including beefier bumpers and the optional 22-inch wheels of this car - provide additional distractions. The X5 is far from pretty, but its scale alone gives it road presence, while also ensuring the cabin is spacious and practical. It's smart, too, with BMW's wide infotainment screen and digital instrument cluster offering great functionality - especially now that Apple CarPlay is standard - although it can't come anywhere near close to challenging Land Rover's interior for pizzazz.
That being said, the BMW does not feel short on quality because it is extremely refined, with the near silent electric motor making for a relaxing driving experience around town. Ask for more than the e-motor and 24kWh battery can provide - BMW claims 50 miles can be eked out between charges - and the petrol engine starts contributing seamlessness. It remains hushed in volume, producing a smooth six-pot hum that's only really audible when the radio's off. Progress feels swift yet effortless. BMW's fourth-gen electric tech is well polished these days, and nowhere is that clearer than in the brake pedal, which feels completely natural despite the energy recuperation tech the system employs. If there's a negative to note, it's that the PHEV charging system won't accept a fast charger.
But with the petrol engine onboard, you can at least hold charge until you arrive in a zone (such as a city) where electric running is preferable. In EV mode, the car is actually plenty quick enough for urban driving, but on the open road the petrol motor is essential. When up to speed the X5 45e feels every bit as brisk as you might expect, with super quick throttle response and a great sense of mid-range muscle. But coupled to the quietness of the six-cylinder, you're never beckoned to work the powertrain hard, nor does the ride encourage particularly enthusiastic driving. There's clearly a focus on comfort here, with the 45e lifting over crests and leaning around corners, albeit in a well-controlled way. The damping does a fine job of keeping things in check given the onerous nature of the payload, although plainly the weightiest X5 is tuned with unruffled progress in mind. Under duress, it often wants a second to settle - and its 'Sport' mode is more interested in sharpening the throttle response than turning up the damping.
Nevertheless, the 45e does what it says on the tin, bridging performance and economy in a practical, spacious package. With all that kit on board it's not cheap, as illustrated by the X5 driven which adds over £12k of options to the model's £65,760 starting price. But you are getting a broadly capable machine for that figure, one that will take advantage of the latest company car tax bracket benefits thanks to its modest electric range and low CO2 output. No less important is the quality of performance on offer from its six-cylinder engine, which leaves the four-pot-based Volvo Twin Power alternative looking somewhat outclassed. Expensive it may very well be, but it's likely the best option currently available in a fast-growing hybrid SUV segment.
SPECIFICATION - BMW X5 45E
Engine: 6 cyls in line, 2998cc, turbocharged petrol, plus electric motor
Transmission: 8-spd twin-clutch automatic, all-wheel drive
Power (hp): 394 (combined)
Torque (lb ft): 442 (combined)
0-62mph: 5.6 secs
Top speed: 146mph
Price: £65,760 (price as tested: £78,235, including £2,095 technology pack, £2,350 comfort package, £1,900 M Sport Plus pack, £645 22-inch wheels, £2,440 panoramic glass roof, £700 adaptive LED headlights, £2,345 rear seat infotainment)