An eco-friendly, petrol-electric hybrid drive is now the only choice for Lexus’ middleweight GS model - and quite right too, says motoring journalist Steve Loader

Assailed by the global warming, social responsibility, congestion and parking arguments, to name but a few, it’s harder than ever to justify owning a bigger car, even if you can afford it.

But not all such cars are bad, as I found with the Lexus GS300h. This is the new entry version for the Toyota luxury brand’s BMW 5 series basher, since it decided to give up trying to sell petrol-only GS variants and concentrate on the petrol-electric hybrid or ‘h’ powertrains that are the marque’s hallmark.

So, the GS450h flagship (from £49,495) was joined by the more affordable GS300h (from £31,495). Describing cars like this as ‘like driving an armchair’ is a cliché, but I make no apology because it really is and to the point where some reviewers say it wallows a little on corners. So what?

If you have chosen a big saloon like this, are you really looking to throw it around like a sports coupe? Anyway, there are enough nutters out there at the wheel of SUVs believing they are part of an SAS rapid response team, without others joining in.

What most big car buyers today want is the traditional refinement, space and comfort of the type, plus economy to soothe the wallet and eco conscience. The GS300h delivers on all of those.

But the last point is what this car is really about: the petrol-electric drivetrain and its back-up batteries mean the GS is often running in electric-only ‘EV’ mode at lower speeds, making it that rare beast: an economical yet big town car.

Its worst side is high-speed motorway cruising, when the 2.5-litre petrol engine shoulders much of the burden, but none of it is bad news and the Lexus always feels refined and unflustered.

Driven with a light touch, you should average around 50mpg in all situations, while 113g/km of CO2 emissions places it in the ‘C’ road tax band – free for the first year and just £30 in following years, making it an all-round tax beater for company car user choosers. And the more you drive it, the more you realise how well the hybrid set-up works best for bigger cars, despite Toyota’s success with its smaller Prius.

You have more space and bulk in which to lose the battery pack, and the bigger engine means performance is still highly respectable or even sporty (0-62mph in 9.2 seconds) when petrol and electric power are pressed to work hard in tandem.

There is also something deeply satisfying when you see the car’s eco gauge show the batteries are being charged when the car is coasting or braking.

The GS comes with a seven-speed auto gearbox, with manual selection available on the centre selector or via F1-style paddles on the wheel, meaning the car can be hustled, even if its armchair ride comes at the price of that slightly soft cornering.

Looking beyond the technical, cabin quality, a clear dashboard arrangement and high- quality sound system, plus competitive specification for the money are all Lexus traits. This is particularly so if you step up to the Luxury version driven here, which adds leather upholstery, heating and ventilation front-seat functions and sat nav. n