Background
The RX is an important car for the Lexus brand to get right. It shouldn't be its best selling global model, but at the launch of this MK5 version it was, so re-imagining the whole concept behind this long-running model line wasn't without risk. But the market for full-size luxury SUVs is evolving and Lexus felt this fifth generation RX should evolve with it.
So it is that there is now a Plug-in Hybrid version - and a ground-breaking Turbo Hybrid too. There's also an all-new GA-K platform, a very different interior and media connectivity on another level from before. Lexus promises that you can even now enjoy driving this car with a bit of vigour. Whatever next?
Driving Experience
In the past, no one has ever bought RX because it's exciting and engaging to drive, but Lexus wants to change that. For the first time in a long time - several generations - the brand has had a complete re-think about how this car should handle, possibly because it now sits on a completely new and much stiffer GA-K platform. From that surer foundation, the engineers have added a new 'Direct4' torque vectoring 4WD system for better tarmac traction through the turns. And developed handling to create what the brand calls the 'unique Lexus driving signature'.
The engines - all petrol-powered of course - are different too; there are now three. Things kick off with the RX350h, a 2.5-litre normally aspirated self charging full-Hybrid powertrain with 242bhp and performance similar to the old RX450h (0-62mph in 8.0s). Most customers though, are expected to opt for the RX450h+, the RX model line's first Plug-in Hybrid. This uses the same engine as the RX350h, but pairs it with a rear-mounted electric motor for full-time 4WD. The result is a 302bhp output and 62mph in 7.0s, though you'll have to drive less frantically than that for the 18.1kWh battery to yield its promised EV range of 40 miles.
At the top of the range sits an engine that's new not only for the RX but also for Lexus and the industry as a whole: a Turbo full Hybrid - fitted to the RX500h. You can't plug this flagship variant in, but it will drive like no other RX has before, with 366bhp supplied by a 2.4-litre engine and a pair of electric motors that deliver the full-time 4WD system: 62mph is dispatched in just 5.9s.
Design and Build
The RX gets a new visual lease of life in this fifth generation form, with a more dynamic look clearly influenced by the brand's full-electric RZ model and the smaller NX. This so-called 'Next Chapter' design language delivers a more confident stance and emulates the 'spindle body' profile of the RZ. The stylists were going for a more coupe-like feel, dropping the roofline by 10mm, plus there are big 21-inch wheels and sleeker LED headlights. There's just the standard body shape this time round.
Inside up-front, there's a more driver-focused minimalist dash, with a standard 14.0-inch central infotainment touchscreen and the usual digital instrument cluster. That'll be new for RX folk, as will be the "Hey Lexus" voice control system, the wireless 'Apple CarPlay'/'Android Auto' smartphone-mirroring and the cloud-based services that enable 'always-on' connectivity for things like traffic reports. There's vegan leather upholstery and the front seats are heated and cooled. Plus there's a customisable ambient lighting system with 64 colours and 14 pre-set themes. In the rear, a 60mm wheelbase increase frees up useful extra leg space. And out back, there's bigger boot too, 50mm longer than the previous model's.
Market and Model
Prices sit primarily in the £62,000 to £78,000 bracket, so there's a step up from the previous model. To compensate, Lexus has introduced many advanced human-centred technologies in the RX to enhance comfort, convenience and life on board, reinforcing the spirit of its brand's 'omotenashi' hospitality.
The RX can be specified with a digital rear-view mirror which gives the driver a wide, unobstructed field of vision, using real-time images from the car's reversing camera. For easier driving in confined spaces, the Digital Panoramic View Monitor uses cameras to capture a live 360° view around and a pre-recorded view under the car. And an Advanced Park system is also available which provides automated control of the steering, shift operation and braking and uses the car's array of four cameras and 12 ultrasonic sensors to gain an all-round picture of the immediate surroundings. It will also recognise up to three regularly used parking spots.
All models of course get the usual 'Lexus Safety System+' safety package, which here offers upgraded functions and increased scope for accident risk detection and prevention. The improvements include further expansion of the Pre-Collision System's ability to detect motorcycles and other objects in the car's path. It can also recognise collision risks with oncoming traffic or crossing pedestrians when making a turn at a junction. Its detection response is quicker and the ability to avoid an impact is increased by Emergency Steering Assist. Enhancements have been made to the Adaptive Cruise Control so that it now more quickly recognises traffic cutting in in front and, in conjunction with upgrades to Lane Trace Assist, follows a more natural line through bends.
Cost of Ownership
Let's get to the figures. The base RX 350h returns between 42.2 and 44.1mpg on the combined cycle and between 143 and 150g/km of CO2. For the top RX 500h, you're looking at between 33.2 and 34.5mpg on the combined cycle and between 182 and 189g/km of CO2. The RX 450h+ Plug-in Hybrid obviously does a lot better. The figures there are between 235.4 and 256.8mpg on the combined cycle and the tax-beating CO2 emissions reading is between 24 to 26g/km.
Whichever kind of RX you decide upon, at higher speeds, you'll need to bear in mind that the quoted fuel figures are even more heavily dependent than normal on the driver assuming a significant degree of restraint. Certainly, for noteworthy levels of frugality in day-to-day use with this Lexus, you'll need to keep the powertrain operating setting in 'EV' mode as often as possible. And frequently twist the 'Drive Mode Select' dial near the gearstick into its left hand 'Eco' mode, which moderates throttle response and engine power output while tweaking the climate control. Plus you'll also need to keep a very careful eye on the Hybrid system indicator on the left hand side of the instrument binnacle, making sure that the needle stays as often as possible in the light blue 'Eco' zone.