► We drive the new Lexus RX450h
► Retains established hybrid drivetrain
► Which is not necessarily a good thing
You get a lot of Lexus RX450h for Mercedes GLE or Volvo XC90 money, but in the end the RX lives or dies by its hybrid drivetrain, with its promise of slashing fuel consumption and CO2 emissions. In real life, however, Lexus seems to be treading water as far as its hybrid technology is concerned. Where is tangible progress like a modern plug-in layout, lithium-ion batteries or a frugal lightweight combustion engine to partner the e-motors?
‘We know how to do a modern PHEV,’ says chief project manager Takayuki Katsuda. ‘But the plug-in technology is expensive, it carries a weight and packaging penalty, and it only makes ecological sense when powered by CO2-neutral electricity. The full hybrid is affordable, reliable and popular. It has helped the RX to attract 2.2m customers over time.’
Although the aggregate power output of the drivetrain has gone up from 296bhp to 310, the key hardware elements are familiar: a normally-aspirated 3456cc V6 rated at 263bhp, a 167bhp electric motor co-driving the front wheels and a separately operating rear propulsion unit good for an unchanged 68bhp. The peak combined torque is in the area of 332lb ft. The stepless CVT transmission has eight virtual ratios and drives only the front wheels. Rear-wheel drive is purely electric, which makes much more sense in town than off the beaten track where the car’s weighty front end can get stuck before the tail summons sufficient push. On the road, part-time awd is bound to improve traction and grip as you approach the limit of adhesion, but since the hind legs act late and abruptly, they don’t do all that much to improve the staid handling. Weighing up to 2.2 tonnes depending on spec, the RX takes 7.7sec to hit 62mph. While the top speed is limited to 125mph, Lexus is quoting an impressive 54.3mpg. Why impressive? Because beyond regular filling station visits, this cordless hybrid must generate its own supplementary energy.
The new RX is longer (by 120mm) and wider (by 10mm), it offers 50mm more rear legroom but still no third row of seats. More slippery (Cd: 0.32) and quieter than last year’s car, it can be had with various new assistance systems which are programmed to keep you on course, swiftly yet safely. All perfectly in line with the character of a model less interested in power than in efficiency, refinement and the sound quality of up to 15 speakers. Like its precedessor, it offers a smooth ride, low noise and Bentley-esque cabin.
So why don’t we love the RX like the Americans, who buy most of them? Because there’s nothing here for the keen driver. The howling rubber-band-effect CVT ’box, the nose-heavy handling, the uncommunicative steering and the flaccid brakes all make us frown. Although this is a compelling freeway wafter, it lacks mid-range punch, long legs and the faintest trace of interest in going round corners. When pushed, it swiftly becomes edgy and stressed, but the ho-hum dynamic talents can be improved by specifying adaptive dampers, active anti-roll bars and bigger tyres.
The RX relays a strong feelgood message. It can’t match its European rivals for overtaking urge, but at the end of a leisurely cross-country journey it’s the Lexus driver who will feel more relaxed and – in a broader context – more satisfied.
The spec: Lexus RX450h
Engine: 3456cc 24v V6, 263bhp @ 6000rpm (310bhp with electric motors), 332lb ft @ 4600rpm
Transmission: Eight-speed CVT, four-wheel drive
Performance: 7.7sec 0-62mph, 125mph (ltd), 54.3mpg, 120g/km CO2
Weight: 2105kg (est)
On sale: January
Love: Build quality, plush ride
Hate: Uninvolving handling
Verdict: Ageing hybrid system fails to convince