If you judged a car entirely by its sales figures, you’d be forgiven for thinking the Kia Optima was a bit of a clunker.

In 2014, Kia UK shifted just 736 of the things, with figures for 2015 showing little more in the way of interest, either.

Admittedly, a large part of this apparent despondency lies with Kia’s admirable refusal to shovel the things into the fleet sector with massive discounts and – perhaps to a greater extent – the large saloon car market having all but shrivelled up.

But if you look further afield to the US, you’ll discover last year’s Optima was the brand’s best-selling car, racking up nearly 160,000 units all by itself.

So do the Yanks know something we don’t?

We think the answer’s yes, because the Optima is probably the best car you’ve never heard of.

…the Optima is probably the best car you’ve never heard of…

For 2016, it’s received a whole slew of revisions that almost qualify it as an entirely new car.  For a start, it’s longer and wider than last year’s car, complete with bulging wheel-arches and the company’s ‘tiger nose’ grille that’s filled with an appealing ‘star field’ design.

This is flanked by new larger headlights that include an automatic high-beam assist function on some models – although it’s a shame they’re not LED units – and these are joined by LED fog-lights that look like something out of War of the Worlds.

The boot-lid has a more aerodynamic trailing edge, the bumpers have been re-profiled, there’s a neat oval exhaust pipe, and the rear lights now feature LED illumination and a funky light signature at night.

For this year, Kia have redesigned the dashboard to deliver a greater focus on the driver, but they’ve also taken the opportunity to upgrade the quality of the materials.

Satnav comes as standard across the range, although lesser models have to make do with a slightly smaller screen, but they make up for it with DAB digital radio and beautifully clear instruments.

Mid-range and above models come with a 590W Harmon Kardon set-up that remains remarkably distortion-free even at high volumes, although one small annoyance is that the system doesn’t remember your last volume setting, instead reverting to a predefined start-up volume that you can’t set to zero.

What has us set on the Optima, though, is the sheer amount of cabin space – it’s truly vast.  And thanks to the increase in wheelbase and overall width, there’s even more of it on offer than there was before.

There’s business-class levels of legroom, shoulder-room has been increased over the old model, and there’s plenty of headroom for rear-seat passengers despite the sloping roof-line.  In fact, short of something like a long-wheelbase Mercedes, I can’t think of another car with this much interior space.

…short of a long-wheelbase Mercedes, I can’t think of another car with this much interior space…

There’s even a huge boot to go along with it.  It’s slightly larger than before, now at 510 litres, and you can fold the rear seats forward if you need even more space.

Probably about the only thing about the Optima that’s small is the engine.  At the moment, it’s only available with a 1.7-litre turbodiesel with 139hp, although there are plans to introduce a 2.0-litre turbocharged petrol unit with 245hp as part of a new GT model.

Towards the end of this year, there’ll also be a plug-in hybrid model that’s expected to offer a 33-mile electric-only range.

For now, though, the diesel is hardly lacking in green credentials, and in manual form it emits just 110 g/km of CO2 and records up to 67.3 mpg on the official tests, while we averaged just over 50 mpg during our time with it.

It’s punchy through the gears, with peak torque arriving at just 1,750 rpm, and the six-speed ‘box has a light yet positive action that makes it a pleasure to use.

The Optima is also available with a seven-speed dual-clutch transmission that, although we haven’t tested it yet, probably suits the Kia’s character a little better.

Kia have made substantial changes to the suspension for 2016, and the result is a much smoother ride.  The new set-up also does a decent job of containing body-roll, and this helps give the Optima a surprising feeling of agility.

However, despite improvements to the steering, there is still a slight over-eagerness either side of the straight-ahead position, and although it still feels stable at speed on a motorway, it can feel a little inconsistent.

We also wouldn’t object to little more bite from the brakes – the power is there, it’s just that it requires a little more pedal pressure than you initially think.

Nit-picking aside, the Optima is an incredibly relaxing place to spend time while tackling a long journey.

It’s also incredibly safe, with top-spec models boasting both short- and long-range radar systems to detect obstacles and apply the brakes if necessary, together with an adaptive cruise control function, while mid-range models get a new Lane Keep Assist system that can even steer the vehicle within its lane entirely automatically.

The fact all of this can be yours for just £21,495 is, frankly, remarkable.  Plus it comes with a seven-year, 100,000-mile warranty.

What really impressed us about the Optima, though, is just how far it punches above its weight: the last time I drove a car that offered this much interior space, it was something with a cat on the bonnet and a price tag almost three times that of the Kia.

Admittedly, the diesel engine is perhaps the weak link in an otherwise endearing package, but that only makes us more excited to see what the forthcoming GT and hybrid versions will be like.  Plus there’s an estate version on the horizon in the form of the new Sportswagon.

It doesn’t seem long ago that Kia made largely beige cars for beige people.  Somewhere along the line, though, it seems the entire company got out of bed one day and collectively declared “no, we’re going to do better.”

While the Optima probably isn’t quite there yet, it’s definitely the most surprising car I’ve driven in a long time.

Tester’s Notes

  • Driver-focused dash layout; clear instrumentation
  • Satnav standard
  • Stereo turns on with ignition to pre-set level, can’t set to zero
  • 590W system sounds good if a little mid-heavy
  • Truly incredible cabin space for all occupants
  • Large boot with folding seats
  • Diesel-only engine line-up is only weak link
  • Six-speed manual has positive shift action, well balanced clutch action
  • Impressive wind noise isolation
  • Steering a little inconsistent around straight-ahead
  • Brakes need more pedal pressure than is reassuring
  • Compelling warranty package; keen pricing
  • The most surprising car you’ve never heard of
  • Can’t wait for the GT model
Entry-level Price £21,495 Price as tested £24,040
Engine 1.7-litre 4-cyl turbodiesel Transmission 6-speed manual
Power 139hp @ 4,000rpm Torque 340Nm @ 1,750-2,500rpm
0-62 9.7 secs Top speed 121 mph
Economy 67.3 mpg CO2 110 g/km
Dimensions 4855 x 1860 x 1465 (LxWxH) Kerb Weight 1515 kg