Ten or 15 years ago, in the early days of hybrids, it was difficult to imagine a time when three electrified drivetrains would come along at the same time, make such a positive impression and all win spots on the Wards 10 Best Engines list.
And yet, for the first time ever, that’s exactly what happened this fall with the Hyundai Sonata plug-in hybrid, Chevrolet Volt extended-range EV and Toyota Prius hybrid.
In general terms, all three make the list by delivering groundbreaking battery-powered electrical propulsion paired with first-rate, high-efficiency internal-combustion gasoline engines. Two heads truly can be better than one, as all three demonstrate.
Relative to these three entries, the hybrids of the past tended to rely on older gasoline engines, some of them off the shelf. Amazing what happens when engineers are turned loose with equal vigor to focus on both the electrical and the gas-driven components of a hybrid.
Hyundai’s 2.0L direct-injection 4-cyl. wasn’t sitting around waiting for an application. No, Hyundai engineers took a reasonably new engine (codename “Nu” ironically, evaluated just two years ago for Wards 10 Best Engines) and reworked it specifically for hybrid duty.
Horsepower was reduced 12% and torque 10%, which is a direction we generally frown upon. But here it makes sense because the 9.8-kWh lithium-polymer battery and 50-kW (67-hp) electric motor are making up for any shortfall from the gasoline engine.
In addition, the engine was reconfigured to run on the fuel-saving Atkinson combustion cycle, which enables a high compression ratio (13.5:1 vs. 11.5:1 two years ago) and higher thermal efficiency.
Also new is an electric water pump, which improves fuel economy and makes for faster engine warmup and better coolant temperature control. Cooled exhaust-gas recirculation to reduce pumping losses, a 2-stage oil pump to optimize oil pressure and reshaped intake ports and improved combustion stability all make the 2.0L Nu a much better engine.
Why PHEV Is Better Than HEV
But let’s not overlook the electrical side of this outstanding powertrain, which combines for 202 hp in the plug-in Sonata hybrid.
The standard Sonata hybrid, also new this year, wasn’t bad either and scored reasonably well in the competition, but the lower-voltage system makes only 193 hp.
It’s the plug-ability that makes the winning Sonata so interesting. Have access to a standard electrical socket each night? Plug in and count on a full charge within nine hours. During the day, plugging in at a 240V Level 2 charger will top off the battery within three hours.
A fully charged battery delivers EV range of 27 miles (43 km) until the gasoline engine is called upon for heavy lifting.
We plugged in daily, which explains the astonishing fuel-economy numbers on the trip computer, with 46.5 mpg (5 L/100 km) minimum. Most people cranked it well into the 60s and 70s, and one lucky editor saw 80 mpg (2.9 L/100 km) for a spell, thanks to regular charging.
The battery pack is roughly five times larger than that of the Sonata Hybrid, but the PHEV doesn’t feel much heavier than the standard hybrid.
The electric motor, mounted in place of a torque converter within the 6-speed automatic transmission, is 32% more powerful than the motor used in the Sonata Hybrid.
Still on the fence and wondering whether to buy the hybrid or plug-in hybrid? Initially available in 10 zero-emissions states, including California, New York, New Jersey, Oregon and Massachusetts, PHEV buyers will be eligible for $4,500 in various federal tax credits and have access to high-occupancy vehicle lanes.
In first-quarter 2016, customers in the remaining 40 states will be able to order a Sonata PHEV at their local dealerships.
The Sonata PHEV is a sizable and stylish car that looks a lot more expensive than its $34,600 base price. To experience this world-class drivetrain brings quick realization that it’s a bargain.