The fifth-generation RX lays claims to many new firsts to vie with its German rivals. Al Suttie weighs up its fighting chances.

Lexus RX 500h F Sport White

List price (BiK): £77,195 (37%) CO2: 182g/km Economy: 35.3mpg Test efficiency: 26.5mpg

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Monday

Revolution tends to come quietly at Lexus, and not just because of its electrified drivetrains. In the case of this RX 500h, the significant changes are twofold – more power and a change of transmission. First off, the 2.4-litre four-cylinder petrol motor and electric motor combo now produce 366bhp. Secondly, the CVT (continuously variable transmission) has been replaced by a conventional six-speed auto.

Tuesday

With more power and a gearbox that should lend itself to a more engaging drive, I’m keen to try the RX 500h on some twisty roads. The countryside around Loch Lomond provides that opportunity and there’s no doubt this large SUV is brisk when pulling out of junctions. It doesn’t have the decisive, almost thuggish acceleration of a BMW X5 plug-in hybrid, but the Lexus has not trouble passing slower cars.

Wednesday

Fun on twisty roads is all well and good, but the RX 500h is a car built with cruising in mind and it does this to perfection thanks to its superbly insulated cabin. There’s a little bit of noise when the four-cylinder engine is working hard, but it quickly settles, leaving the Lexus to waft you along in near silence and superb comfort. The six-speed auto is also near seamless in its changes to emphasise comfort.

Thursday

In contrast to the white exterior of this car, the interior is finished in quite a vibrant shade of red that mixes leather and suede. There’s a louche 1960s Las Vegas casino restaurant vibe that I’m not sure whether I really like or not. Still, there’s no questioning the amount of space inside the RS or the excellent support of the driver’s seat with its wide range of adjustment.

Friday

A small but consistently annoying trait of the Lexus RX 500h, and others in the company’s range, is the door release pull. Rather than just pulling it once, you have to tug it twice to release the door. It may be a safety feature, but it’s one that feels wholly unnecessary, especially as the release handle is about the only ergonomic gaff in the RX’s cabin.

Saturday

Sitting on sizeable 21-inch wheels, I was concerned the ride quality of the RX might suffer during my driving time. However, it manages to be more than supple enough on Scotland’s less-than-well-kempt roads and there’s very little noise generated in the cabin from the tyres. With four-wheel steering as standard, too, the RX feels nimble in town and when tackling roundabouts or country lanes.

Sunday

With no EV-only driving range in the RX 500h, unlike the RX 450h+, claimed fuel economy comes in at a so-so 35.3mpg. This was showing as 26.5mpg on the dash display, though I have to admit to a heavy right foot as I enjoyed the RX’s performance on plenty of occasions. I suspect the RX is a car that will endear the more you own it, but on this brief encounter I think its main rivals have its measure.