Two versions of the GS are available; the GS250 has a 2.5-litre V6 petrol engine, while the GS450h has a hybrid system that combines a 3.5-litre V6 petrol engine with an electric motor. The GS250 is too sluggish, with 207bhp and a paltry 187lb ft of torque to call on for such as large car. The GS450h has a combined 338bhp and is much swifter. It needs to be worked hard, though, and the CVT gearbox is frustrating.
The standard GS450h rides comfortably and handles well enough, but there's a degree of slack in the body control and steering that make it feel its size on twisty roads. Top-spec GS450h F Sport models have a rear-wheel-steering system that gives significantly crisper turn-in to corners, however, even if you select the firmest suspension setting, the ride is far from harsh.
The GS 250’s V6 engine sounds rough when worked hard, which you need to do all too often. The GS 450h has a Continuously Variable Transmission (CVT) gearbox that sends the revs soaring and its engine also becomes coarse when pushed. Admittedly, at low speed you can coast around in electric-only mode, creating little more than a whisper. Wind- and road noise isn't an issue on either model, but there’s less of each in a BMW 5 Series.
The GS450h averages 47.9mpg and emits 137g/km of CO2, which is comparable with six-cylinder diesel rivals, but can’t compete with rival four-cylinder diesel execs. The GS250 averages just 31.7mpg and has CO2 emissions of 207g/km – 12.4mpg less and 58g/km more than a BMW 520i automatic. List prices are on the high side, and resale values aren’t likely to be anything special.
Lexus has an exemplary record in most of our JD Power customer satisfaction and annual reliability surveys. There’s nothing to suggest the GS will let the side down and the cabin feels built to last. There’s lots of plush leather, too, but some of the plastics and switchgear would look more at home in a Toyota that costs half as much.
Lexus has thrown everything at the GS when it comes to safety kit – as well as a stability control system there are no less than 10 airbags. Top-spec Premier models are available with LED headlamps and a preventive safety package that includes Adaptive Cruise Control and a pre-crash safety system. All the security kit you’d expect of an executive saloon is present and correct.
The GS has a supportive driver’s seat and a decent range of adjustment for that and the steering wheel. Visibility is fine, too. The dashboard has a lot of switches, but the huge information screen at the top of the dash is easy to read. Lexus’s ‘Remote Touch Interface’ system, which is standard on higher-spec versions, has a computer mouse-style controller and is overly fiddly.
The GS’s cabin is reasonably roomy, although it doesn’t provide as much space as you might expect in such a big car. The cabin certainly isn’t as practical as the GS’s German rivals. Rear legroom is plentiful, but foot space is rather limited and headroom – front and rear – is tight for anyone more than 6ft tall. The boot has a decent outright capacity, but it’s unusually short.
The GS doesn’t out-rank its German rivals in many areas, apart from this one. Even entry-level SE trim includes leather upholstery, electric front seat and steering wheel adjustment, a rear-view camera and DAB radio. Beyond that, Luxury and Sport models supply an increasingly lavish range of extras. At the pinnacle, Premier trim includes three-way climate control, Mark Levinson stereo and automatic boot closing.