As part of Kia’s mission to lower its fleet average CO2 by 25% before the end of the decade has yielded the company’s first plug-in hybrid model; the Optima PHEV.
Boasting a range of up to 33 miles in all-electric mode, the Optima PHEV returns CO2 figures of just 37g/km. The Optima PHEV combines a 154bhp 2.0-litre direct injection petrol engine with a 50kW (67bhp) electric motor powered by a 9.8kWh lithium-ion polymer battery pack. The electric motor replaces the torque converter in the smooth-shifting six-speed automatic transmission. When working together, the combustion engine and motor generate 202bhp and 375Nm of torque.
A package of aerodynamic, styling and technology features contributes towards the Optima PHEV’s low CO2 emissions and potential fuel economy of up to 176.6mpg. The most significant aerodynamic change is an active air flap grille which lowers the car’s drag co-efficient (Cd) to 0.25 when closed. The integration of the batteries behind the rear seat and in the spare wheel well, along with a 15-litre reduction in the car’s petrol tank, means the Optima PHEV is still offers 307 litres of luggage space.
Hybrids are not new to Kia, but they have never previously been brought to the UK because diesels offered greater tax advantages in the all-important company car market. The all-new Optima PHEV, with its extended all-electric driving range, low CO2 emissions and ultra-low company car tax rating, redress this balance and will be an important fleet car for Kia in the UK.
The core feature of the hybrid system is the ‘next-generation’ 9.8kWh lithium-ion polymer battery pack, which produces significantly more energy than that in previous Optima hybrids. Meanwhile, the relative simplicity of the hybrid system allows compact packaging of the petrol engine, electric motor and automatic transmission on the front axle, with minimal energy transfer and conversion losses.
This results in up to 33 miles of pure-electric driving at speeds as high as 75mph, with 0-60mph acceleration in 9.1 seconds in hybrid mode. The switch between electric and hybrid driving is seamless, while the electric motor’s 205Nm of torque from standstill ensures instantaneous response to the throttle pedal.
The Optima PHEV is equipped with a number of technological innovations to help it use the power in its battery pack in the most efficient way and top up its batteries on the move.
The car utilizes a number of technologies, such as regenerative braking, a driving style guide, an ECO-DAS (ECOnomy Driver Assistance System) featuring Coasting Guide Control, a Drive Mode Select button so that drivers can personalise the powertrain’s dynamics, and an HEV (Hybrid Electric Vehicle) Select switch. It also has an intelligent heating, ventilation and air conditioning (HVAC) system to save battery power.
HEV Select gives access to two driving modes via a button in the centre console. In EV (charge depletion) mode the car runs as a purely electric vehicle when the energy stored in the batteries is adequate, and is able to regenerate electrical power on the move to recharge the batteries. The Optima PHEV has an all-electric driving range of up to 33 miles. HEV (charge sustaining) mode allows the powertrain to balance the use of motor and petrol engine for a seamless combination of electric and internal combustion power. In this mode, a greater proportion of propulsion comes from the petrol engine and the charge level of the batteries is constantly being topped up for later use.
The Drive Mode Select gives the driver the choice of Eco and Normal settings. A driving style guide delivers information through the instrument panel about how efficiently the car is being driven so that drivers can adapt their driving style as necessary.
Kia’s regenerative braking system, now in third generation guise in the Optima PHEV, allows the car to harvest kinetic energy when coasting or braking.
The advanced HVAC system has been adapted from that in the Soul EV, and permits only the driver’s side of the car to be cooled when the other seats are unoccupied to minimise energy usage. It does this through a smart air intake, in contrast to rival systems which merely divert the airflow towards the driver when other vents are closed and consequently do not reduce energy consumption.