Yet another joins the hybrid ranks, and this one is from Korean automaker Kia. The company introduced its new Kia Optima Hybrid Sedan at the 2010 LA Auto Show, and the vehicle is slated to make its US market debut early next year.
It’s equipped with a parallel hybrid system, where a 2.4 litre Theta II Atkinson cycle petrol engine is mated to a small electric motor and drives the front wheels via a six-speed automatic transmission, without the traditional torque converter.
The car’s 30kW Interior Permanent Magnet (IPM) synchronous electric motor – described by Kia engineers as a Transmission-Mounted-Electric-Drive (TMED) – sits within the car’s extended transmission casing between the petrol engine and the automatic gearbox, and is the world’s first oil-cooled system.
A special clutch is fitted between the engine and motor, enabling the petrol engine to be de-coupled from the powertrain so that Optima can be operated in zero-emissions, full-electric drive mode from standstill up to 100 kph. Such is the configuration that a high-capacity electric motor and generator isn’t required, thus saving weight and cost.
When setting off, the Optima Hybrid operates in Electric Mode, and as the vehicle speed rises, the 8.5 kW Hybrid Starter motor/Generator (HSG) starts the petrol engine and the clutch is closed, allowing the engine to take over the task of propelling the car. The electric motor switches into hybrid operation and serves as both a secondary engine (during full acceleration and hill-climbing) and a generator to recharge the battery pack as necessary.
The motor offers 30 kW (40 hp) and 205 Nm of torque from 0 to 1400 rpm in electric mode, and the combined hybrid powertrain of electric motor and engine puts out 154 kW (206 hp) and 265 Nm. Performance specs include a 0-100 kph time of 9.2 seconds, a top speed of 195 kph and a combined fuel economy of 6.2 litres per 100km, which is a significant improvement over a bog standard Optima.
Battery-wise, the car employs a 34 kW lithium polymer battery array developed in partnership with LG Chem. Compared with nickel-metal hydride batteries, lithium polymer batteries weigh 20-30% less, occupy 40% less volume, are 10% more efficient and can hold their charge 25% longer than NiMh units.
So reliable is the battery pack, which weighs in at just 43.6 kg, that a replacement isn’t needed for at least 10 years/250,000 km, says the company.
The Optima Hybrid gets a few tweaks to help it along, aerodynamically speaking – the car is lowered by 5mm and new features include an active air flap in the front grille, smooth underfloor panels, low-drag wheels and low rolling resistance tyres, all helping to reduce the drag coefficient to 0.26Cd.
Gallery after the jump.
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