Kia’s midsize Optima sedan got an exterior and interior “freshening” for 2019, the first key changes since the gasoline-only models moved into their fourth generation for 2016 and the hybrid versions arrived in their second generation for 2017.

There are four gasoline-only trim levels for 2019, starting with the LX 2.4 ($22,900, plus $920 freight), followed by the S 2.4 ($24,900), EX 1.6 Turbo ($26,800), and the top-of-the-line SX 2.0 Turbo ($31,900), which we tested with no options.

For 2019, there are two hybrid models: the base EX for $27,985 plus $920 freight, and the EX PHEV — plug-in electric hybrid — for $35,290.

The PHEV model’s hybrid battery pack can be connected to an external power source for recharging, which means that it can run on electric power alone if the battery is kept charged and isn’t allowed to run down. If the battery does run down, though, the PHEV can continue going on its gasoline engine, just like the regular EX hybrid. The plug-in model was added to the hybrid lineup for 2017.

Three gasoline engines are available in the gas-only models, beginning with a normally aspirated 2.4-liter inline four-cylinder, standard in the LX and S models, with 185 horsepower and 178 foot-pounds of torque. This engine is connected to a six-speed automatic transmission.

EX models get a turbocharged 1.6-liter inline four-cylinder with 178 horsepower and 195 foot-pounds of torque, mated with a seven-speed, dual-clutch performance automatic transmission.

Our SX model came with the most-powerful engine option: a turbocharged 2.0-liter inline four-cylinder rated at 245 horsepower and 260 foot-pounds of torque. It’s paired with a different six-speed automatic transmission.

The hybrids have a 2.0-liter, 154-horsepower four-cylinder gasoline engine, coupled with a 50-horsepower electric motor in the standard model, or a 66-horsepower motor in the plug-in version.

Total combined output of the engine and electric motor is 192 horsepower and 271 foot-pounds of torque in the base hybrid, and 202 horsepower and 276 foot-pounds of torque in the PHEV.

As for the 2019 changes, the Optima got some new design features inside and out, but not enough to qualify it as a new generation. It also received expanded Advanced Driver Assistance Systems technology, new UVO infotainment options, and available European-inspired red and black two-tone sport leather-trimmed seats (standard on the SX),

There are also new alloy wheel choices, ambient LED interior lighting, and a new Passion Red exterior color. Our SX model came with a Sparkling Silver exterior and black interior (except for the two-tone seats), and 18-inch alloy wheels.

LX models get new Kia Stinger-inspired LED daytime running lights, new 16-inch alloy wheels and a matte gray grill.

S — or Sport — models now have projector-beam fog lights, LED taillights, dual exhaust, sport side sills with gloss-black trim, a gloss-black grill, and 18-inch alloy wheels. They also come with a smart key with push-button start, smart trunk, and power front windows with auto up/down.

Besides the 1.6-liter turbo engine and dual-clutch transmission, the EX now has an adaptive Smart Shift drive mode; new leather seats with front-seat heaters; new 17-inch alloy wheels; Smart Cruise Control with Stop-and-Go; and the fog lights, LED taillights and dual exhaust from the S model. Options include multicolor interior lighting and a heated steering wheel.

SX models can be dressed up further with the SX Limited Package ($3,800, not included on our tester).

New LED fog lights, ambient interior lighting, sport steering wheel and Smart Cruise Control with Stop-and-Go are standard on the SX model, which also comes with a panoramic sunroof; Harman Kardon premium audio system with UVO link and navigation; heated steering wheel; gloss-black door pillars and side moldings; and a sport bumper with LED fog lights.

In the hybrid models, there is a lightweight, high-density lithium-polymer battery pack, placed under the trunk floor.

Unlike some hybrid sedans — such as the Toyota Prius — the Optima hybrid looks almost identical to its gasoline-only sibling. But the hybrid does have a few unique styling cues, including a front air curtain, beveled rear bumper, rear diffuser shrouding the exhaust tip, and aerodynamic alloy wheels.

Included on our SX was the hands-free smart trunk opener, which automatically pops the trunk lid open if someone stands behind it for more than three seconds with the key fob.

Among standard safety features are front seat-mounted side air bags, roof-mounted side-curtain air bags for both rows, driver’s knee air bag, electronic stability control with traction control, antilock disc brakes, hill-start assist, and tire-pressure monitoring.

We had an abundance of power from the 2.0-liter turbo engine, with very little sign of turbo lag or the torque-steer effect often associated with front-drive cars.

Our time in the SX included a weekend trip with three adults on board, and occasionally four or five in the car for restaurant and sightseeing outings. The front seats are quite comfortable, as are the rear outboard positions. The middle position is OK for a small adult or child, but tight for a larger person.

The ride was smooth and reasonably quiet, even on some bumpy roads.