SNOWMASS VILLAGE, CO – When we reviewed the third-generation Kia Optima in 2010 we called its looks “stunning.”

It’s an opinion many in and outside the auto industry held, and a key reason why Kia decided to stay the course on styling for the fourth-gen Optima, arriving now at U.S. dealers.

We can’t blame them, especially as the Optima continues to hold its own in WardsAuto’s Lower Middle car segment, a battleground now more than ever with Americans flocking to compact and midsized CUVs.

Showing the outgoing Optima’s resiliency, Kia’s share of the Lower Middle group is holding steady at 6.5%, while bigger-name competitors lose market share, causing the segment as a whole to lose 1.0% share of U.S. light-vehicle sales through October.

The good news is the move to keep the Optima’s design language static isn’t a fumble. Its soft angularity, or in Kia-speak “sweeping, contemporary surfaces,” still looks fresh after five years.

The new car isn’t an exact copy of the old one. The tiger-nose grille is updated, now longer in length and shorter in height than before, and taillights are a bit bigger and placed higher, overlapping the ends of the trunk lid.

Wheels are pushed even further to the corners for the low-and-wide stance every OEM covets.

Unfortunately a 0.4-in. (10.2-mm) increase in the wheelbase doesn’t make much of a difference in passenger space. More on that later.

Given five years gone since its last full redesign, the Optima’s body is built with 150% more high-strength-steel than the outgoing third generation.

More than half of the body, including side rails and A-pillar and B-pillars, is composed of HSS which not only improves crash protection, but driving dynamics, and also makes for a quieter ride.

About that last point, the relative solitude of the cabin is perhaps the biggest noticeable change while driving a ’16 SX Turbo Launch Edition grade here last month.

Kia employs the industry-typical slew of insulating materials to stop engine, road and wind noise from infiltrating the passenger space.

An increased amount of structural adhesives, from 20 ft. (6 m) to 120 ft. (37 m), also helps increase cabin solitude.

Benz-Like Seats, But Comfort Mixed

While it’s a quiet space, visually the ’16 Optima’s interior has taken a slight step backward.

Kia says it invested heavily inside the Optima, but most of the money appears to have gone to the seats.

Ours are swathed in merlot-colored Nappa leather and quilted in a diamond pattern. They are beautiful, on par with Mercedes-Benz and Audi seats.

However, hard-plastic surfaces seem rougher than before and soft-touch areas glossier.

The seats and their real stitching, also seen on the steering wheel and center console bin lid, overshadow the plain-jane door panels that have no metallic trim to dress them up.

The Optima’s seats, despite their four layers of foam, feel so-so. The back cushion is supportive, but the bottom cushion is too short and doesn’t adequately elevate thighs, which is especially noticed during hours of interstate driving.

The rear seat still is cramped, despite the car’s slightly bigger footprint.

Middle-seat headroom is especially tight, with this 5’8” reviewer’s noggin touching the ceiling.

Outboard rear-seat legroom is just OK.

The center stack continues to be an area where Kia shines.

The Korean brand and Fiat Chrysler have the best maps in the business, due to their big, bright and crisp touchscreens with large virtual buttons.

Especially nice is the ability to zoom in and out right on the screen, saving us from hunting in menus for the function.

Real buttons remain big and are placed low, making them an easy reach for both driver and front passenger.

A minor gripe is smallish, shallow knobs for radio and heating-system controls.

Two Turbos, One Naturally Aspirated, All Direct-Injected

The new Optima offers three powertrains, all direct-injected fours, mimicking sister brand Hyundai’s strategy with the Sonata.

However, the largest-displacement engine, a naturally aspirated 2.4L, remains the base mill, powering the LX entry grade as well as the midgrade EX and making 185 hp and 178 lb.-ft. (241 Nm) of torque at 6,000 and 4,000 rpm, respectively.

Optional on the LX is Hyundai/Kia’s 175-hp DI 1.6L with a single-scroll turbocharger mated to a 7-speed DCT, creating a low-priced Eco grade.

A short Detroit-area jaunt in an LX 1.6L shows its 195 lb.-ft. (264-Nm) of torque, coming as low as 1,500 rpm, is plenty for everyday driving. The engine does exhibit some slight low-end hesitation in gas-sipping Eco drive mode, however.

The SX and SXL grades again have a 2.0L turbocharged and DI 4-cyl., but with 66% new parts including a smaller, higher-speed dual-scroll turbocharger.

In keeping with Hyundai/Kia’s recent move to reduce rarely used maximum horsepower and lower the torque peak, the engine now is rated at 245 hp vs. 275 hp at 6,000 rpm and 260 lb.-ft. (353 Nm) vs. 269 lb.-ft. (365 Nm) coming in as soon as 1,350 rpm instead of 1,650.

The 2.0T’s maximum torque bests not only competing 4-cyls., but also V-6s, including the 3.5L’s in the Camry (248 lb.-ft. [336 Nm]) and Nissan Altima (251 lb.-ft. [340 Nm]).

The 2.0T meets every challenge we throw at it, with the exception of slow torque delivery upon accelerating to 40 mph (64 km/h) from 30 mph (48 km/h) on State Highway 82 heading toward Aspen.

The SX Turbo Launch Edition nearly is a premium sport sedan in disguise, tearing up the twisty mountain roads with aplomb and remaining flat in corners and with minimal body roll no matter how hard it’s pushed.

Kia credits the Optima’s larger and lighter (by 44 lbs. [20 kg]) chassis for improved stability at higher speeds, while a revised overall suspension geometry allows for shock absorbers to be upright and makes for better wheel placement in cornering.

The SX and SXL get an upgraded steering system, a rack-mounted power-driven type first seen on the new Sorento CUV.

A 32-bit processor, also on the Optima LX and EX’s column-mounted steering system, makes steering respond faster to inputs, something that was evident during our day of Colorado driving.

Most of our miles here are in Normal drive mode, but we test Eco and Sport. The biggest change is seen with Sport steering, which has a notably firmer feel. Acceleration is similar across the board, with the car pulling just as quickly in all three modes.

Real-world fuel economy is impressive.

While we can only muster 17 mpg (13.8 L/100 km) on an up-mountain route through the Rockies in the SX, afternoon routes down mountains and on flat highways result in a 36-mpg (6.5-L/100 km) average. That clobbers the car’s stated EPA combined estimate of 26 mpg (9.0 L/100 km) and the LX 1.6T’s combined estimate of 32 mpg (7.4 L/100 km).

The untested LX and EX with the 2.4L are rated at 28 mpg (8.4 L/100 km) combined.

The Optima’s average fuel economy is up 1-2 mpg (0.4-0.9 km/L) from ’15.

Kia offers its typical high level of standard equipment across the board on the new Optima, and further premium-izes the SX by offering Harman/Kardon’s 10-speaker, 630-watt audio system with the Clari-Fi music-restoration technology also seen on the new Lexus RX CUV. The system is standard on the SXL and also optional on the EX grade in combination with a premium package.

Kia holds pricing on the LX, its best-selling grade, from ’15 at $21,840, while the new LX 1.6T is $23,990.

The ’16 Optima EX begins at $24,890, up from $450 from ’15, while the SX and SXL are $29,690 and $35,790, up roughly $2,000 from their outgoing models.

The latter number sounds like luxury territory, but it’s difficult to find any midsize premium car for less than $40,000 nowadays.

And based on the prior Optima, a good chunk of buyers (40%) want those high-end models.

Despite comfort and interior-material issues, we think the Optima SX and SXL are worth the cost based on sharp looks, a high level of niceties, refinement and performance.

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’16 Kia Optima SX Specifications