2011 Hyundai Sonata Hybrid leapfrogs the competition

Korean company has vaulted to the head of the pack with its very first hybrid.

Published: November 1, 2010, 5:00 PM

2011 Hyundai Sonata

San Diego, CA Just as the new conventional version has tackled the best in the class and racked up sales that require an extra shift at the American plant where they are built, the hybrid version sets new standards on a number of areas. Let there be no doubt this is a company equipped to take on the best.

Hyundai has no false hopes for the 2011 Sonata Hybrid. It knows it will sell 300-500 or so in Canada in a year. That has been the story at Ford and Toyota where sales of hybrid versions on the Fusion and Camry have totalled about 650 units a year combined.

why bother then? Hyundai poured its considerable resources into the hybrid version of the new Sonata as a way of showing the world it can compete at any level. Not only does its hybrid compete · it beats the others on many fronts.

Hybrids use a conventional internal combustion engine paired with a powerful electric motor and a large pack of batteries. "Full" hybrids like the Prius, Fusion and Camry can operate on either the electric motor or the gasoline engine or both. The Sonata does this as well, just better.

The new Sonata Hybrid uses a version of the company's own Theta four-cylinder engine. In this application it produces 166 hp and 151 lb-ft of torque. The hybrid·s electric motor produces 40.8-horsepower and a further 151 lb-ft of torque at zero rpm.

The result is a combined total of 206 hp compared to 187 for the Camry and 191 for the Fusion. You can·t simply add the peak power figures of the IC engine and electric motor to get a total because they don't reach peak power at the same time.

The other hybrids use a Continuously Variable transmission (CVT) that maintains a constant engine speed while vehicle speed increases. This is highly efficient in terms of fuel economy but very unpleasant under heavy throttle applications such as merging or passing situations because the engine screams at its most efficient rpm (usually 4,000-5,000) while the vehicle catches up.

Hyundai engineers found a way to use a modern six-speed automatic transmission in the Sonata Hybrid. The result is a more pleasant series of subtle gear changes, a more conventional feel. They also did this in a way that saved weight and size · the slim but powerful electric motor resides inside the transmission housing in place of the normal torque converter. The electric motor supplies the torque multiplication normally provided by the torque converter.

The others typically use nickel-metal-hydride batteries to power their electric motors. In their upcoming newer versions many hybrid manufacturers are switching to smaller, lighter lithium-ion batteries like those used in laptop computers and cell phones.

It can also handle more charge-discharge cycles before storage capacity begins to degrade. In durability testing the Sonata batteries have lost only 10% of their power after 300,000 km. Testing continued past 450,000 km.

Another area where Hyundai decided to separate itself from the pack was the decision to maximize highway instead of city mileage.

The traditional fuel economy advantage for hybrids comes in city driving where the engine shuts down when the vehicle is at a rest and the electric motor kicks in to add some punch when moving. However these hybrids offer little if any advantage over their conventional counterparts on the highway.

Hyundai has the engine shut-down and electric assist features for excellent city mileage · but has superior highway mileage thanks to the six-speed transmission. It gives up a little in the city but gains it back, and more, on the highway. Hyundai expects the Sonata Hybrid to be rated for 5.4 litres/100 km highway. Hyundai says its research shows that more than half of North American driving is done on the highway.

There are other little unique features as well. Thanks to the lithium-polymer batteries the Sonata is lighter than the competition and with more power, has a performance advantage.

An active air flap behind the grill opens at low speed and when coolant temperatures are high, but closes the rest of the time for improved aerodynamics resulting in quicker warm-ups and a 10% reduction in the power required for slipping through the air.

The power-steering, brake and air-conditioner pumps are electric so there is no power lost to turning belts and they continue to operate when the engine is shut down briefly at rest.

Otherwise the Sonata Hybrid drives and feels exactly like its conventional twin quiet, spacious, extremely well-equipped and built. It can be driven at higher speeds than the others on pure electric power  I got it up to almost 100 km/h before the IC engine kicked in. Thanks to the six-speed automatic there is little to no way you can tell it is a hybrid - until you get to the gas pumps!

Look for the Sonata Hybrid in spring 2011 wearing 'Hybrid Blue Drive' logos It will come in a fully-loaded premium trim level only with pricing expected to be in the $32,000 range.

Hyundai has gone one step further, leap-frogging over lithium-ion to lithium-polymer technology. Developed in conjunction with LG, the 270-volt battery pack in the Sonata hybrid consists of 72 individual cells behind the rear seat. It is smaller, lighter and has greater power density than nickel-metal-hydride or lithium-ion equivalents.
Hyundai has vaulted to the head of the pack with its very first hybrid. In a remarkable show of technical prowess the South Korean company has come out of nowhere to show just how capable its engineering department is.