In diesel loving Britain, an executive saloon is nothing if it can’t offer decent fuel economy and, crucially, the low CO2 emissions that drive down company car rates for business buyers. Lexus has traditionally struggled in this market with sales of its GS saloon lacking compared to its German rivals, due to its refusal to embrace diesel, instead championing hybrid technology as the future of efficient motoring. The Japanese brand is hoping to fix that with the introduction of a more efficient hybrid engine, badged GS300h, to the range.

What is it?

The second full hybrid offering in the GS line-up. The drivetrain was first introduced in the smaller IS saloon and sees a 2.5-litre four-cylinder petrol engine mated to an electric motor for a combined 220bhp. While it may be slightly down on the 333hp produced by the 3.5-litre hybrid unit found in the GS450h, it usefully lowers CO2 emissions to 109g/km (115g/km as tested here due to larger optional alloy wheels), meaning lower tax and Benefit In Kind costs. Those who’d prefer to do without all the hybrid kit can opt for the GS250, which is powered by a conventional, normally aspirated 2.5-litre V6 motor, developing 206bhp.

What is it like to drive?

56.5 mpg

220 bhp

For drivers looking for a tranquil way of getting to and from the office, the GS’s hybrid system trumps the comparably frugal diesel offerings in its German rivals, with its on-board battery offering silent progress at slow speeds for short distances. Instead of being greeted by a cacophony of diesel clatter on startup, there is nothing but a feint hum, which remains distant as you accrue speed.

Stray above 30mph or accelerate too briskly and the petrol motor will make itself heard, providing extra power to the wheels, or topping up the battery. Despite this mechanical intrusion, the GS remains hushed and refined. It’s comfortable, too, with only the sharpest surface abrasions making themselves felt in the cabin.

119mph

Top speed is credible for such a large and economical car

Up the pace and the GS makes less sense. The CVT gearbox, which is the only transmission option available on hybrid models, neuters the feeling of speed from behind the wheel, seemingly serving up more noise than forward propulsion. A relatively slow 0-62mph sprint time of 9.2 seconds backs this up in objective terms.

In the corners, the GS is stable and composed, though lacks the suppleness of the driver’s choice BMW 5 Series. There is enough poise to the chassis to make a drive on a winding road entertaining, but it’s clear the GS leans more towards effortless wafting than it does white-knuckle B-road blasting.

What is it like inside?

Those used to the build quality of Japanese cars of old will be pleasantly surprised by the GS, as in terms of material and construction quality, it is certainly on a par with its competition from Mercedes and Audi. The design, however, is distinctly un-German, with some interesting surface touches on the dashboard. And, eschewing the rotary controllers of BMW and Mercedes, Lexus is the only brand we’ve come across to fit a mouse to drive all of the sat-nav and entertainment functions, via what is one of the largest infotainment screens in this sector.

Equipment levels on Lexus models are traditionally generous, and this mid-range F-Sport model certainly didn’t disappoint, being fitted with cruise control, dual-zone climate control, Bluetooth connectivity, adaptive variable suspension and LED interior lighting, some choice highlights from a long list of toys.

Passengers will find plenty of lounging room, no matter which seat they occupy, and will stay comfortable even on the longest journeys thanks to some fabulously supportive seats.

Is it practical?

The GS’s saloon shape, and lack of rear folding seats limits the loading of bulky objects in the rear. That said, the boot itself is relatively commodious, at 547 litres in size, and is usefully deep and square, despite the concealment of the hybrid system’s battery pack beneath it.

Practicality is further enhanced by all-round parking sensors, which, complete with visual aids, make negotiating tight spots easier – something you’ll be thankful for given the car’s not inconsiderable girth.

Should I buy one?

If you’re a business buyer and want a premium executive saloon that will offer the cheapest possible running costs, the GS300h should definitely be on your shopping list. It’s unique styling and hybrid tech means it has broader appeal amongst private buyers, too. However, if you’re looking for an entertaining drive, you’re better off with one of the Germans.

Don’t want to buy new? You can browse for a used Lexus GS in our classifieds.

The facts

Lexus GS 300h F Sport

List price: £41,745
Price as tested: £44,355
Engine: 2.5-litre, four cylinder petrol, electric motor
Power: 220bhp
Top speed: 119mph
0-62mph: 9.2 seconds
Fuel economy: 56.5mpg (urban), 57.6mpg (extra-urban) 56.5mpg (combined)
Emissions: 115g/km CO2
Euro NCAP rating: Not yet tested