The ES 300h – to be launched in Western and Central Europe – is equipped with a new, fourth generation self-charging hybrid drive system that can deliver exceptional fuel efficiency, responsive performance and minimal emissions for a mid-size luxury sedan. It couples an ultra-efficient 2.5-litre Atkinson cycle four-cylinder petrol engine with a lighter, more compact and more power-dense electric motor. Total system power is 218 PS/160 kW and combined cycle fuel economy is from 4.7 l/100km.
The 2.5-litre engine is all-new and incorporates fast-burn combustion technology that makes it one of the most thermally efficiency engines to feature in a production vehicle. The result is more power without increasing emissions or fuel consumption. Features that help achieve such impressive results include straight intake ports, increased valve angles and laser-clad valve seats. A variable-capacity oil pump, multi-hole injectors, VVT-iE on the intake valves and a variable cooling system also contribute to the engine’s impressive heat and combustion management.
Designed specifically to work with the 2.5-liter engine, the new transaxle utilizes a multi-axle arrangement of the electric motors in place of the previous coaxial setup to reduce the overall length of the package by nearly 30mm. The traditional planetary gear set has been replaced by a parallel shaft gear and a multi-function gear that incorporates a power split planetary ring gear, parking gear and counter drive gear into one compact unit.
The nickel metal hydride battery that powers the electric motor has been relocated from the trunk to underneath the back seat. This was made possible by a 120mm reduction in the height of the battery and the adoption of a more compact cooling system. Moving the battery under the seat not only frees up trunk space, it also improves the front to rear weight distribution of the ES for better handling.
Several new features have been incorporated into the ES 300h to improve overall driving satisfaction and engagement. The hybrid control system is now designed to deliver a more linear acceleration feel by aligning engine speed more closely with vehicle speed to reduce the rubber band feel commonly associated with hybrid systems. Engaging the Sport drive mode further enhances acceleration by boosting torque at lower speeds while paddle shifters can be used to move through six simulated gears for more precise control.