Overall rating:

Lexus has never had a diesel GS and continues in that vein for the fourth generation. However, the new hybrid is even more efficient than before and yet just as quick. As a bonus, it finally has a usefully sized boot. It's a tad expensive though.

Key Facts

Model driven: Lexus GS 450h Luxury
Price: £44,995 (GS range starts at £32,995)
Engine: 3.5-litre V6 petrol engine mated to AC synchronous electric motor
Transmission: Electronic-Continuously Variable Transmission (E-CVT), rear-wheel drive
Body style: four-door saloon
Rivals: Audi A6, BMW 5 Series, Jaguar XF
CO₂ emissions: 141g/km
Combined consumption: 46.3mpg
Top speed: 155mph
0-62mph: 5.9 seconds
Power: 345hp total system maximum
Torque: 352Nm at 4,500rpm for engine, plus 275Nm for motor
Boot space: 465 litres

In the Metal:

The more expensive models in the new GS line-up - specifically the more aggressively styled F Sport version - look more interesting, though overall the new car brings Lexus' design language to the GS size successfully - if in a subdued manner.
In contrast, the interior is awash with interesting details and is of the highest quality. Soft leather abounds and every switch operates with satisfying precision. The three-spoke steering wheel is a particular delight and we also love the design of the analogue clock. We're not so enamoured with the digital readouts for the climate control, nor the action of the Remote Touch Interface, though no doubt an owner will soon get used to such things.
Crucially, boot space has been increased by 55% over the outgoing car's - thanks to repositioning of the battery pack.

Driving it:

Comfort and refinement are the name of the game in the new GS. Though Lexus has sharpened up the steering and added a Sport mode, the new car should never be compared to the likes of the BMW 5 Series for driver interaction. This Luxury model does without the adaptive damping so the fixed settings are optimised for comfort. It excels at cruising and is a highly relaxing car to travel in. In town that's aided further by switching into EV (electric vehicle) mode, which is virtually silent.
Not that that V6 petrol engine is noisy. Most of the time it's completely inaudible. Even if you put your foot down it emits a cultured sound, without ever being loud. Do that and, following a brief delay as the transmission decides what best to do, the GS is hurled forward with real vigour. There's no reason to question the impressive 5.9-second 0-62mph time, nor the maximum 345hp output.
And while the GS's chassis copes with the performance, it doesn't encourage you to use it all. This is a car built for cruising and it's something it does very well - even at relatively high speeds.

What you get for your Money:

Lexus will offer the GS 450h in three grades: Luxury at £44,995 and both F Sport and Premier at £50,995. All three versions are in VED band E thanks to 141g/km emissions and combined economy is as high as 46.3mpg. Impressive figures for such a car - and comparable with many of the diesel offerings from other brands. However, the purchase price of the GS puts it into contention with higher-end versions of the likes of the 5 Series, A6, E-Class and Jaguar XF.
The Lexus is generously equipped. Even the Luxury model tested here features the full arsenal of safety equipment, rear view camera, auto lights and wipers, 17-inch alloys, heated door mirrors, aux-in and USB ports, Bluetooth, a leather interior with heated and ventilated front seats (also electrically adjusted) and dual-zone climate control - and much more.

Worth Noting

The amount of technology squeezed into the new GS is staggering, but the air conditioning system fitted to the Premium model got our attention. First up, if you select 'S-Flow' the system changes its output based on whether or not it senses occupants in each of the passenger seats. Vents are automatically shut in those areas to enhance efficiency. Along with that the system incorporates what Lexus calls 'nanoe' technology. Here's how it works:
'It releases 20 to 50Nm diameter nanoe particles - negatively charged ions wrapped in water molecules - into the cabin via the driver's side dashboard air vent.
By attaching themselves to airborne particles and molecules, the nanoe ions have been said to have both an air purifying and odour eliminating effect. They also deodorise vehicle seats and ceiling to create a cleaner cabin environment.
In addition, because nanoe moisture content is approximately 1,000 times that of conventional ions, the emission of ions bonded to water molecules is said to have a moisturising effect on skin and hair, acting to enhance occupant well-being.'

Summary

If you're in the market for a high-end premium saloon and you reckon there are enough Audis, BMWs, Jaguars and Mercs around, the Lexus GS may be ideal. The GS 450h, the only version to have, is highly refined and comfortable, efficient, quiet and packed with technology and equipment. It's not cheap mind.