Despite the multiple drive modes, the 740Le is no harder to drive than a diesel 7 Series. As long the car has charge, you simply press the starter button, drop the transmission into drive and pull away in complete silence. It’s a serene experience that feels perfectly in tune with a car of this type.
Depress the throttle pedal farther and the electric motor powers the BMW up to B-road speeds with minimal effort. It’s an impressively flexible electric unit and one that endows the 740Le with a level of low-speed refinement that its diesel-powered siblings can't hope to match. Air suspension fitted to both axles also does an impressive job of smoothing out undulating surfaces and isolating rear passengers from the outside world.
Switch the adaptive chassis settings from Comfort to Sport, and while the 740Le is far from being an engaging driver’s machine, there's fun to be had hustling it down a country road. The steering is direct enough, the four-wheel drive system provides heaps of traction and the chassis has an intrinsic balance that competitors such as the Mercedes-Benz S-Class struggle to match. Combined with rapid straight-line pace, the ‘carbon core’ 7-Series is a well-polished and well-rounded machine – for most of the time.
Unfortunately, like all plug-in hybrids, the 740Le is not completely without fault. We’re pretty confident that you could get near the claimed 134mpg figure if you drove carefully and charged the BMW every time you stopped, but that’s not realistic, but on our recent journey from London to Paris, for example, we only averaged 34.2mpg. Ultimately, if you’re doing a lot of miles, a diesel still makes more sense.
Depleting the battery like we did on our trip also leads to another problem. With no electric motor to drive you away from the lights, what you’re left with is a two-tonne car powered by a rather gruff sounding 2.0-litre petrol engine. Granted, the active engine mounts do a good job of isolating the cabin from vibrations, but the aural harshness of the highly-strung four-pot is hard to ignore.
Thankfully, in this long-wheelbase version you escape from the noise up front by sitting in the well-appointed rear. With heated, massaging seats, twin screens and a snap-in tablet computer, it’s a relaxing place to sit, and the £4675 Bowers & Wilkins sound system fitted to our car sounded superb whether or not you see that as good value.
However, for any airport chauffeurs who are currently tempted by the idea of a luxurious cabin and low-cost city driving, just be aware that the 740Le’s 420-litre boot is 90 litres smaller than you get in the standard diesel or petrol 7 Series. That’s because the lithium ion battery pack now sits under the rear seats, forcing the fuel tank back and above the rear axle.