2017 Kia Optima Plug-In Hybrid

The plug-in hybrid remains a strange automotive safety blanket. It tries to combine the virtues of both electric and internal-combustion propulsion, but, like those who’d wear both belt and suspenders, it’s compromised by a fundamental lack of certainty. By the standards of the genre, the new Kia Optima plug-in hybrid is good; given the low price of gasoline, though, it feels like the answer to a question that few actually ask.

Although the Optima PHEV (plug-in hybrid electric vehicle) is Kia’s first plug-in, it shares mechanical components with the existing Hyundai Sonata plug-in. (Kia also will continue to sell a plug-free Optima hybrid alongside the standard Optima sedan.) The PHEV’s 154-hp 2.0-liter four-cylinder engine works in conjunction with a 67-hp electric motor/generator to deliver a peak system output of 202 horsepower. A six-speed automatic with the electric motor replacing the torque converter drives the front wheels. The transmission is equipped with an electric oil pump in the interest of efficiency.

The big difference from the regular Optima hybrid lurks under the rear seats and trunk floor: a 9.8-kWh lithium-ion battery pack that, Kia claims, allows the PHEV to go up to 29 miles in electric-only mode and to operate at speeds of up to 75 mph without firing up the gasoline engine. (Kia had predicted only 27 miles of EV range when it revealed the car at the Chicago auto show in February.) Twenty-nine miles is one of the longer EV ranges in the plug-in segment, well short of the Chevrolet Volt’s 53 miles but 50 percent beyond the Toyota Prius Prime’s 22. It takes about nine hours to recharge using a 120-volt supply but only three hours if you have access to a Level 2 240-volt connection.

Cosmetically, the PHEV is distinguished by its automatic active grille shutters, which, according to Kia, reduce the car’s drag coefficient to just 0.25 when its louvers are closed. It also has its own lower-drag front and rear bumpers and a subtle but noticeable blue tint to both the headlights and the exterior chrome brightwork to set it apart from less eco-minded Optimas. Equipment includes the usual battery of energy-monitor displays and the Economy Driver Assistance system (ECO-DAS), which gives visual and audible advice on when to let the car coast. We quickly confirmed that the system’s admonitory chimes can be switched off.

As is common with plug-in hybrids, the big battery pack exacts a weight penalty. Kia’s numbers say the PHEV weighs a Rubenesque 3788 pounds, or 302 more than the regular hybrid and 564 pounds heftier than the Optima 1.6T. The battery pack also robs the trunk of three cubic feet of capacity when compared with the standard Optima, but that still leaves a decent 13 cubes.

The Costs and Benefits of Redundancy

At lower speeds, the Optima PHEV disguises its mass well. The electric side of the powertrain gives it the usual instant EV response, and even when left in its default hybrid mode, the majority of low-speed urban operation relies on pure electric power as long as the battery has charge. The driveline doesn’t manage the magic-carpet impression that hybrids with variable-ratio planetary gears convey under gentle use, but the automatic’s stepped ratios mean it doesn’t suffer from slurred transmission response when the driver orders quicker, gasoline-propelled progress. Drivability issues that we noted when we tested the 2014 Optima hybrid seem to have been addressed; the electric and gasoline sides of the powertrain now work together seamlessly.

EV mode is great for sneaking up on pedestrians and for polishing your self-image as an eco-aware consumer. Otherwise, EV mode’s main advantage is lower carbon emissions compared with the car’s operation in standard HEV (hybrid) mode. Given the growing number of cities that forbid combustion engines in their congested center zones, EV mode is likely to become more appreciated over time.

Initial acceleration is reasonable under electric-only operation, but it tails off early as speed builds; it would take a long, gentle run-up to confirm the claimed EV-mode top speed of 75 mph, since anything beyond gentle pressure on the accelerator fires up the engine. In the gentle use that the car encourages, refinement is good, but once the internal-combustion side of the powertrain gets going, it proves raucous at higher revs.

Try to hurry things along, and you’ll run up against the unwelcome effects of the PHEV’s extra pounds. Grip levels are modest on the low-rolling-resistance tires, and the Optima struggles to keep its mass in check when asked to deal with tighter corners or bumpier roads. The steering is both overboosted and completely lacking in feel, so your eyes will have to warn you when the PHEV’s front end starts edging wide of the mark at velocities that would trouble few other mainstream cars. The springs and dampers struggle to control ride motions on rougher road surfaces, even at fairly modest speeds. Dynamically, the Optima PHEV seems to fall short of the Toyota Prius.

The rest of the experience approximates that of the standard Optima. The cabin leaves the impression of plastics that were chosen more for durability than appearance, but it offers good space for four occupants. We drove a Euro-spec version in Korea, but we know the PHEV model due to appear in U.S. dealerships later this year will be in the EX trim level with a fairly generous array of equipment.

A Short-Range EV

Anyone in the market for a plug-in hybrid should already be aware of the compromises inherent to this neither-fish-nor-fowl formulation. For anything other than relatively short journeys between destinations equipped with fast chargers, that large battery pack becomes a liability rather than an asset. Chevy supports the case for its extended-range Volt with the assertion that most commuters travel fewer than 40 miles a day, round trip, so a relatively modest range gives owners the equivalent of a pure electric. Kia expects the Optima PHEV to earn an EPA fuel-economy rating of 99 MPGe, but once the big battery is depleted, real-world mileage will be worse than that of the standard hybrid owing to the extra mass and essentially identical operating parameters. Unlike some plug-ins, it can recharge its big battery pack on the move, in the conventional hybrid manner, using regenerative braking and the engine—but you’d have to be moving at a crawl or idling for a long while before it’d replenish meaningful EV range.

A driver’s usage would have to be heavily biased toward slow urban slogs, covering short distances, to make the math work. As plug-in hybrids go, the Optima PHEV is decent, but unless gas prices spike dramatically, the whole segment struggles to justify itself as a mass-market solution.

Specifications >

VEHICLE TYPE: front-engine, front-wheel-drive, 5-passenger, 4-door sedan

ESTIMATED BASE PRICE: $35,000

ENGINE TYPE: DOHC 16-valve 2.0-liter inline-4, 154 hp, 139 lb-ft; permanent-magnet synchronous AC motor, 67 hp, 151 lb-ft; combined power rating, 202 hp, 277 lb-ft; 9.8-kWh lithium-ion battery pack

TRANSMISSION: 6-speed automatic

DIMENSIONS:
Wheelbase: 110.4 in
Length: 191.1 in
Width: 73.2 in Height: 57.5 in
Passenger volume: 105 cu ft
Cargo volume: 13 cu ft
Curb weight (C/D est): 3800 lb

PERFORMANCE (C/D EST):
Zero to 60 mph: 8.0 sec
Zero to 100 mph: 22.4 sec
Standing ¼-mile: 16.2 sec
Top speed: 125 mph

FUEL ECONOMY (C/D EST):
EPA city/highway driving: 38/40 mpg
EPA combined driving (gas+electric): 99 MPGe