Lexus is a luxury brand, so it’s no surprise all the engines are large and powerful. The entry-level 3.0-litre GS300 gets to 62mph in 7.2 seconds and has a top speed of 148mph, while the 4.3-litre V8 GS430 has a 0-62mph time of 6.1 seconds and a top speed of 155mph. January 2008 saw the GS430 replaced by the GS460 – it’s still a V8 but the 0-62mph time has dropped to just 5.8 seconds – that’s as quick as a Porsche Cayman – while economy and emisisons have actually improved.

All the engines are geared towards covering long distances quickly and comfortably, so they cruise at motorway speeds with effortless refinement. But there’s also plenty of power left for overtaking. Acceleration between 50mph and 70mph is as urgent and effortless as that from 0-62mph. The 300 model comes with a six-speed automatic gearbox (it’s a CVT on the GS450h), which suits cruising superbly, but doesn’t offer the kind of crisp changes that are needed for seamlessly tackling cross-county routes.

The flagship 460 gets a new eight-speed auto ‘box which has quicker and smoother changes. The hybrid 450h model has a 3.5-litre V6 plus a compact electric motor delivering a combined 341bhp. This makes it almost as quick as the V8 with 0-62mph achievable in 5.9 seconds. The clever hybrid system uses an electric motor to back up the petrol engine. It adds power when needed, while energy from braking or coasting is used to recharge the battery.

However, while emissions are very low, it only averages 36mpg – less than many similar-powered diesels.

This GS is tauter and sharper to drive than before. The suspension has been firmed up and the wallowy feel of the old model has gone. However, it’s still more at home on the motorway where it cruises smoothly. On more demanding A and B roads, the controls can feel rather remote. The V8 and hybrid models feature an adaptive suspension system with sport settings that firm up the suspension and make the steering more weighty.

However, the GS450h can break the traction of its rear wheels very easily if you’re heavy with the throttle, especially on bends, so it really needs the sophisticated stability control system it features.