Lexus has continued to invest in hybrid drivetrains while others stick with diesel. Since 2005, starting with the RX 400h, every model in the Lexus range has had a hybrid option, from the CT hatchback right through to the LS luxury model.

The BMW 5 Series rivalling GS range, launched last year was no exception, with the 450h marrying up a 3.5-litre petrol engine. But a £50,000 price tag put it out of reach for most buyers.

Now Lexus has put that right by dropping the entry-level 2.5-litre V6 petrol and replacing it with the far more suitable hybrid unit from its smaller IS 300h sibling.

That means a 178bhp 2.5-litre petrol engine sits alongside a 141bhp electric motor, both working in harmony to produce a maximum power output of 220bhp, harnessed by an electronically-controlled CVT gearbox.

This is all very good news for company car drivers, as the CO2 figures drop from the V6’s 209g/km to an altogether more impressive 109g/km on the SE spec. Combined with a much more reasonable price tag of £31,495, drivers could be making significant tax savings against the likes of the Jaguar XF 2.2d and BMW 520d SE.

Fleet managers will also be happy, Lexus claims, as whole-life costs should be almost indistinguishable from the sector favourite, the BMW 520d, while an official fuel economy figure of 60.1mpg over the combined cycle is among the best in class.

With numbers like that, Lexus is hoping to take a larger share of the premium E-segment, intending to double sales to 1,500 units in 2014.

The GS 300h retains the distinctive “spindle” grille that flows in to a collection of aggressive angular lines around the lights and bonnet.

Inside there’s a gloriously sumptuous cabin with a level of craftsmanship that could rival that of cars two or three times the price. Lexus is also persevering with the “mouse” that controls the infotainment system – the equivalent of BMW’s iDrive – though it’s not the easiest of systems to use without spending significant time looking at a screen.

That red lighting encourages you to press on, at which point the GS 300h is found wanting somewhat. The 220bhp available just isn’t that much in what is nearly two tonnes of car, so progress is slower than you might expect.

The CVT gearbox doesn’t help enthusiastic motoring either, allowing the engine to rev hard for extended lengths of time. Thanks to the drop from six to four cylinders, it also doesn’t create the most emotionally engaging noise, but at least the 12-speaker DAB audio system will drown that out.

Kick back and relax though and you’ll find the GS makes a lot more sense. Out on country roads, the engine revs drop and the cabin becomes ever more relaxing. That CVT gearbox is ideally suited to a gentle style, so progress is smooth and efficient, with the car frequently switching to all electric mode.

Verdict:

It may not be quite as good to drive as the BMW 5 Series, but it’s more exclusive and good value if the figures stack up for real. Finally a genuine Lexus rival?

Specification:

Segment: Executive

Type: Petrol-electric hybrid

Price: £31,495–£43,745 

Fuel: 56.5–60.1mpg  

Electric range: 1 mile

CO2 emissions (tailpipe): 109-115g/km

Charging Port: N/A