On the 2016 Sonata Hybrid & Plug-in Hybrid

It’s a few days prior to Memorial Day, the day when gasoline prices have their annual “summer driving” price increase, and while the national average for a gallon of regular is under $3.00 per gallon ($2.744 says the U.S. Energy Information Administration), in California the rise is already well underway, as the average price is nudging $4.00 per gallon ($3.80, says the EIA).

And it is then that Hyundai is introducing its Sonata Hybrid and Plug-In models. This is the second-generation hybrid model; it is Hyundai’s first plug-in.

Scott Margason, director, Product Planning for Hyundai Motor America (HMA) acknowledges that given gas prices elsewhere—he’s talking at the company’s new Gold LEED-Certified headquarters building in Fountain Valley, California—are making electrified vehicles less appealing, (1) product development isn’t instantaneous, so the development of the models has been underway since the price of petroleum was much higher than it is now and (2) “in the long term, we need to keep improving the efficiency of vehicles.”

(According to John Shon, manager of Product Planning at HMA, over 50% of all plug-ins are sold in California. Arguably, under the pre-Memorial Day conditions, things are becoming even more appealing for electrified vehicles for Californians.)

One of the reasons why Hyundai, like all other full-line manufacturers, needs to keep improving the efficiency of its vehicles—which largely means electrification—is because of the need to achieve the CAFE requirements for zero-emissions vehicle (ZEV) compliance.

But Margason says that given things like Federal tax credits for the plug-in (on the order of $4,900) and the ability to drive approximately 24 miles on electricity alone, the car has appeal even in times of comparatively low fuel prices.

So what did they do?

Yong-Seok Kim, general manager, Eco-Friendly Vehicle R&D Center, Hyundai Motor Group, explains that they made a number of modifications to the powertrain of the hybrid vehicle.

Specifically:
• Engine. Downsized it. It is a 2.0-liter, 154-hp engine. Added gasoline direct-injection. The previous generation vehicle was equipped with a 2.4-liter engine.
• Permanent magnet synchronous motor. Downsized it. It is smaller in volume (reduced by 0.4 liter), lighter (by 3.7 lb.), yet more powerful (up 3 kW). The new traction motor produces 35 kW of power. 
• Six-speed automatic transmission. Added a high-voltage electric fuel pump to improve efficiency. (Unlike competitive products like the hybrid versions of the Camry, Fusion and Accord, the Sonata uses a six-speed step-gear automatic transmission, not a continuously variable transmission. The Sonata has its electric motor and clutch attached to the transmission, located where the torque converter would otherwise go.)
• Hybrid power control unit. Lighter by 21% (it weighs 22 lb.) yet has higher power density, up 24% (to 17.7 kVA/L).
• Regenerative braking. Increased energy capture by 11.3%.
• Lithium-ion polymer battery. Increased energy by 13% and power by 19%. The battery pack provides 1.62 kWh of energy and 56 kW of power. One interesting aspect is that whereas in the previous generation the battery was located behind the rear seat in the trunk space, the new battery pack is located in the tire well. Consequently, the cargo volume has been increased from 12.1-ft³Â to 13.4-ft³. As for the plug-in version, the lithium-ion polymer battery package is somewhat larger, as it has sufficient energy storage to propel the vehicle approximately 24 miles (i.e., electric only). Consequently, the cargo volume 
for that version is 9.9-ft³.

The Sonata HEV/PHEV vehicles are based on the seventh-generation Sonata platform introduced as a model year 2015 car. Which means that it has good bones.

That is, 51% of the body-in-white is constructed with advanced high-strength steel (remember: Hyundai owns a steel company, so . . .). Torsional stiffness is 10⁴kg_f∙m²/rad; body flex is 10²kg_f/mm.

However, compared to the conventional Sonata, the coefficient of drag for the HEV/PHEV versions is much better: 0.24 versus 0.27. This is accomplished through such things as front active air flaps, a front fascia design that forms an air curtain that flows across the face of the front wheels, a center floor under cover, a rear spoiler, and spoke wheels with smaller openings to reduce drag.

Margason points out that the drag coefficient of the hybrid models is equal to that of the 
Tesla Model S.

While Hyundai builds Sonatas at the Hyundai Motor Manufacturing Alabama facility in Montgomery, the hybrid versions of the vehicle are being built at a plant in Asan, South Korea.

While the Sonata Hybrid is available throughout the U.S., the Sonata Plug-in is being made available initially in California and Oregon, and then will be rolled out to the other ZEV states (Connecticut, Maine, Maryland, Massachusetts, New Jersey, New York, Oregon, Rhode Island, Vermont).