The Lexus RX performance lexicon involves a 3.5-litre V6 petrol engine working in conjunction with electric motors. It means a total of 295bhp with the petrol and electric motors working together. The RX450h will run on electric-only power at low speeds for a maximum of almost two miles. Batteries powering the electric motor are charged by the engine when coasting or under braking. The electric motor can also ‘assist’ the engine when bursts of speed are required, such as when joining a motorway or for overtaking. Lexus claims a time of 7.8 seconds for the car’s sprint over the 0-62mph benchmark. It comes with a continuously variable transmission (CVT) as standard, which ensures smooth progress, while – with a decent amount of charge in the battery – speeds of up to 25mph are possible for short periods of silent running. This means short trips around town could be done with zero emissions. For drivers who prefer to shift gears manually, there are six pre-set gear ratios which can be accessed with the gear lever in ‘S’ mode.

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Lexus RX customers in the UK have only one choice: the petrol-electric hybrid RX450h. It’s a clever power system and delivers good economy and emissions.

There are different chassis set-ups for the RX450h depending on the equipment grade chosen, but we were impressed with the standard car’s balance and composure. It’s a big improvement over the previous RX, and although an increasing number of 4x4s are being designed to maximise on-road agility at the expense of overall comfort, the third-generation RX seems to have struck a good balance between the two, albeit with pretty inert steering.

Depending on specification, there is a choice of electronically controlled air suspension for greater comfort or an ‘active stabiliser’ for improved agility. The air suspension is fitted to SE-L models, while the range-topping SE-L Premier comes with coil springs and the active stabiliser. Although the active stabiliser car resists body roll better than the standard RX450, the ride quality is poor on anything other than a perfectly flat road surface.

Cars with air suspension automatically reduce the ride height at higher speeds to aid stability and improve aerodynamics. One of the electric motors on the RX450h provides power to the rear wheels (the engine and the other electric motor provide drive to the front wheels) engaging automatically when required. However, the four-wheel drive system is not suitable for prolonged off-road use – merely to improve traction and stability under difficult on-road conditions.