The powertrain itself is a full hybrid arrangement familiar from the NX and RX, combining a 2.5-litre four-cylinder Atkinson-cycle petrol engine with a pair of electric motors for combined outputs of 247bhp and 176lb ft. It isn’t a quick car by any stretch of the imagination, as you might expect, but it still feels much more comparable to a car than a van in terms of its straight-line performance, and indeed a 0-62mph time of 8.7sec (or 9.1sec for the FWD version) is more than sufficiently peppy for such a large vehicle.
It’s eminently manoeuvrable, too, despite its not-insignificant bulk. The expansive glasshouse and HGV-esque mirrors afford excellent visibility at all corners, while a comprehensive suite of parking aids and an impressively tight 11.6-metre turning circle (it’s all relative) will ease the pain when negotiating the airport VIP drop-off ramp or the notorious Savoy Hotel circle.
If pressed to identify a fly in the otherwise silky-smooth ointment, it has to be the CVT. It’s obviously the logical choice for minimising head roll and facilitating a linear, unbroken acceleration path, but there’s no escaping the distinctly unluxurious soundtrack that accompanies uphill acceleration or overtaking manoeuvres. This is a heavy vehicle, at nearly three tonnes, and the drone that permeates both sections of the cabin under load just emphasises how hard that engine is having to work to maintain momentum.
This is less obvious on lower-speed urban jaunts, where the LM switches in and out of EV mode almost imperceptibly to maximise efficiency and, as a by-product, comfort. It makes us wonder whether a plug-in hybrid powertrain, or better yet a fully electric one, might have been a more appropriate means of propulsion for a car of this ilk. But happily its low-speed EV ability does mean it nudges 40mpg on the WLTP combined test cycle, which is no mean feat for a car of such imposing stature and suboptimal aerodynamic properties.
A compelling suite of attributes, then, wrapped up in a subtly striking but somewhat incongruous alternative to the stalwarts of the luxury car market.
For some, the very image of luxury motoring is bound up so intrinsically with gargantuan saloons and SUVs that the concept of swapping into a van (much less one with a Lexus badge) will seem nothing short of nonsensical. But next to the likes of the i7, Mercedes-Benz S-Class and perhaps even the Bentley Bentayga, the LM holds its own as a credible, convincing and highly innovative take on the limousine formula – and one that, true to form, is best enjoyed from the rear.