Hyundai unveiled the refreshed 2018 Sonata at the 2017 New York Auto Show in April -- but only the gas version. While it was fairly obvious that the absent hybrid and PHEV variants would eventually arrive, it took the better part of a year.

The Korean automaker pulled back the cover on the 2018 Sonata Hybrid and Sonata Plug-In Hybrid at the 2018 Chicago Auto Show. Carrying all the same updates as the gas-powered Sonata, this duo of green sedans ramps up the efficiency, thanks to the addition of electric motors.

Visual changes are light and largely relegated to the front and rear fasciae. The bumpers are a bit sharper, and the headlights look a little more aggressive, with the taillights more closely resembling those on the Elantra. Specific to the hybrid and PHEV are two new sets of wheels, as well. The interior gets a mild upgrade by way of a new instrument panel, a new steering wheel and a USB charging port in the second row.

The Sonata Hybrid's gas engine is a 2.0-liter I4 putting out 154 horsepower and 140 pound-feet of torque. Throw the electric motor into the mix, and the net output rises to 193 horsepower. When the EPA gets around to measuring its efficiency, Hyundai believes it'll achieve 39 mpg in the city and 45 mpg on the highway. A single tank of gas can theoretically last for 650 miles. That's Detroit to Chicago and back!

The Sonata Plug-In Hybrid packs a 9.8-kWh lithium-ion battery that provides for an all-electric range of 27 miles. It'll take less than 3 hours to charge the battery on a Level 2 charger. Its 2.0-liter gas I4 combines with its electric motor to produce a net 202 horsepower. The range on this one (with a full battery, mind you) is a little lower, but a still impressive 590 miles.

But the tech doesn't stop at the powertrains. Blind spot monitoring, lane-change assist and rear cross traffic alert are all standard for both Hybrid and PHEV variants. Automatic braking and lane-keep assist are optional. There's also a new 360-degree, bird's-eye-view camera to make parking in tight spots a bit easier, but it can only be had in conjunction with the navigation system.

Speaking of navigation, the standard infotainment screen packs an 8-inch touch display. Apple CarPlay and Android Auto are standard, and options include the aforementioned navigation and real-time HD traffic updates from mapping company Here.

The 2018 Hyundai Sonata Hybrid will hit dealerships in the first quarter of this year, so probably within the next month. The Sonata PHEV, on the other hand, won't arrive until the quarter after that. Pricing has not been announced, but it should be soon, at least for the Hybrid.