It doesn't appear to be a long journey from ES to GS, in fact just a couple of skips through the alphabet, but for Lexus the differences are quite distinct.
We're talking Lexus GS300h here, having been behind the wheel of this sedan a week after returning the smaller ES300h.
Of course there are visible differences and a margin in terms of price as well. While the ES is tagged at $80,995, the bigger and more powerful GS hybrid clips the ticket $25,000 higher at $110,500.
There are obvious similarities between both models and the motive force is the clearest of them.
The 2.5-litre four-cylinder Atkinson cycle petrol engine aligns itself with the two electric motors, which in turn have their own duties to perform. One powers up the batteries and the other kicks in the electric portion of propulsion.
The petrol engine delivers 133kW on its own while the electric motor - one of two on board - produces 105kW. They provide a combined 164kW at any one time.
But the whole point of the GS300h is about making the best use of petrol and electric motors to deliver silky smooth motoring and at costs that would make the secretary of the Treasury grin from ear to ear.
This car is all about open road cruising because the comfort levels underscore that.
When it's running in Eco mode, the power tends to be a little underwhelming. It's only in Sport setting that the car fires into life with any sort of meaning.
But it's all about economy and the maker's claim of 5.2 litres per 100km of urban-highway motoring is miserly stuff indeed. Again it's these figures that give the car its credibility and again emphasises the worth of a hybrid performer.
Drive is through the back wheels and that's handled by a continuously variable transmission that is so unruffled in its delivery you can't detect the changes. But if it's a little more juice you want, then try the sequential shift option either through the gear lever or via the paddles on the steering wheel.
Remembering that the batteries are positioned behind the rear seat, there's going to be some compromise made in terms of luggage space. But even so, the 465 litres is significantly more than what used to be available.
The GS300h epitomises the design brief, which is aimed at making the machine do all the work.
Functions like the automatic park brake - going on or releasing when the car either stops or you drive off - is one of them. Auto headlights and wiper functions are others. And the headlights turn according to the car's direction.
Blind-spot monitors in the side mirrors are a safety bonus while, inside, the front seats boast heating and cooling functions.
No surprise that the front end of the GS looks similar to the ES, with those distinctive arrow-head LED daytime running lights but it does get vents inside the front fog lights. While it's a fraction shorter than the ES, it's wider, taller and with a longer wheelbase.
We mentioned earlier that the Lexus is made for the open road but that's not to say it's a bit gawky around city streets. Far from it, it's as comfortable there as anywhere.
But get it beyond the city lights and it has its chance to shine. Its performance won't peel the enamel off your teeth but you cannot fault its economy, nor the comfort.