So what's the ES experience like? Very quiet, is the answer at the wheel of the ES300h petrol/electric hybrid version, which is the only one on offer in our market. Silence when first you begin and push the starter button. Silence when you ease through slow-moving rush hour traffic, the engine cutting in only above 25mph, unless you've a particularly heavy right foot. Like most hybrids, the car can trickle along powered by the battery pack only (as it is from start-off) or more usually, with a combination of both battery and engine, something you can monitor via a graphic display in the centre of the dash.
Of course, you don't get the kind of pulling power that would be on offer from a rival four cylinder diesel model from rival models in this segment. This ES hybrid's 2.5-litre powerplant puts out 176bhp and only 221Nm of torque. Plus as usual with a Lexus Synergy Drive powertrain, you must have it mated to a belt-driven CVT auto gearbox that, when you need rapid power, tends to encourage engine flare but not a great deal of noticeable extra forward motion. Talking of that, 62mph from rest if you're really pushing on can be dealt with in 8.9s en route to 112mph. And there's a 'Drive Mode Select' system with 'Eco' and 'Sport' settings, depending on how you want to drive. The front driven layout doesn't have the bite of rear-driven German competitors at speed through the turns, but few likely Lexus buyers will care about that.
The looks of this car will be a major determining factor in making people want to try it. Quite a bit has been borrowed from the Lexus brand's top boardroom-level luxury saloon, the LS - and that's a good thing in our book. It gives this ES a car park presence that German rivals struggle to emulate. Under the skin, much might be shared with a humble Toyota Camry, but you'd never know it.
There's much to like inside too. This car is longer, wider and slightly lower than the previous GS model, plus it has the advantage of front wheel drive packaging. All of that combines to produce a noticeably more spacious cabin. This is particularly evident in the rear, where legroom is plentiful. As for head room, well even six-footers will have no problem, despite the siting of the (new, smaller) nickel-metal hydride battery pack under the back seat. Up front, it's just as nice as cabins always are in Lexus models, with beautiful fit and finish and an interesting dash design that's refreshingly different from the fascias served up by German rivals. The infotainment system's an improvement over the set-up's provided in other Lexus models and comes with either an 8.0-inch or a 12.3-inch screen, depending on spec.
There's a single petrol/electric hybrid engine option and a single saloon body style, but three levels of trim - standard, 'F Sport' and top 'Takumi'. ES pricing starts at around £35,000. For the 'F Sport', you'll need around £38,000 and for the top 'Takumi', budget at around the £46,000 mark. All variants are well equipped. Even the base ES has 17-inch alloy wheels, Lexus Navigation with eight-inch central display, a DAB tuner, parking sensors, power-adjustable heated front seats, a sunroof and smart 'Tahara' upholstery. Upgrade to the ES 'F Sport' and you get an F Sport interior and exterior styling details, plus 19-inch alloy wheels, F Sport seats and Adaptive sports suspension.
The top ES 'Takumi' has a power boot lid with a hands-free kick sensor, plus heated and power-reclining rear seats, a 12.3-inch centre-dash display, a Mark Levinson premium surround sound audio, a 360-degree camera, triple-zone air conditioning, triple-eye LED multi-weather headlights with an Adaptive High-beam System and an adaptive front-lighting set-up. All versions come with the Lexus Safety System+ package. A range of equipment option packs are also available, giving customers the opportunity to add bundled additional technology, comfort and convenience features. Particularly popular will be the Premium Pack. This adds leather seat upholstery, front seat ventilation, a lower rear screen sunshade, triple-eye LED multi-weather headlights with an Adaptive High-beam System, 18-inch alloy wheels, Blind Spot Monitoring and Rear Cross Traffic Alert with automatic braking.
This hybrid is of the non-Plug-in kind: which is why it's so much cheaper than German hybrid rivals who only offer Plug-in technology. On to the figures. An ES300h manages up to 59.3mpg on the combined cycle (WLTP) and between 100-106g/km of CO2 (depending on wheel size). In comparison, an Audi A6 40 TDI 2.0-litre diesel model can manage 62.8mpg on the combined cycle and 117g/km of CO2. As you'd expect, to get the full benefit of the potential efficiency of this Lexus, you've got to do your part as a driver - and that means proactive use of the various modes and systems provided.
To get anywhere near the figures being quoted, you'll need to keep the car locked into the 'Drive Mode Select' system's 'Eco' mode, which moderates throttle response and engine power output while tweaking the climate control. Plus you'll also need to keep a very careful eye on the Hybrid system indicator that replaces the usual rev counter on the dash, making sure that the needle stays as often as possible in either of the blue 'Eco' or 'Charge' zones.
Garage visits should cost you significantly less than would be the case with a diesel rival, thanks to the low maintenance requirements built into the Hybrid Synergy Drive system. As part of this, there's no starter motor or alternator to go wrong, no drive belts to break, a maintenance-free timing chain, no particulate filter to get clogged up with diesel fumes and of course, thanks to the CVT auto gearbox, no clutch either.
The car magazines will tell you that most buyers in the full-sized Executive sector expect a highly tuned degree of handling finesse from their saloons. Which of course is rubbish. The average business buyer of a car of this kind wants comfort, luxury and the lowest benefit-in-kind taxation position possible as part of an exemplary low running cost proposition. All of which the ES delivers better than any other contender in this segment.
No, you can't throw it around like a 5 Series or even an A6. The hybrid electric drivetrain can still be frustrating when instant acceleration is called for. And yes, there is a slight whiff of Toyota Camry in some elements of this design. But it's very well disguised. If you're after the most rational choice in the class, you're looking at it right here.