Lotus Hybrid Reaches 0-60mph In Four Seconds

Lotus Engineering has introduced the Lotus Evora 414E Hybrid concept, a technology demonstrator with a plug-in hybrid drive system and technologies for enhanced driver involvement. It can reach 0-60mph (0-97kph) in less than four seconds and has a total hybrid range of more than 300 miles/483 kilometres. It features new developments in plug-in, range-extended electric propulsion, new electronic technologies to enhance driver involvement, Lotus Versatile Vehicle Architecture (VVA) and a new roof system and interior concept from Lotus Design.

Through all of these aspects it ultimately demonstrates the exceptional ability of Lotus Engineering to integrate and develop advanced technologies for exciting, efficient, high performance niche vehicles. The range-extended electric drive of the Evora 414E Hybrid consists of two electric motors driving each of the rear wheels independently via single-speed geartrain, integrated into a common transmission housing, thus enabling torque vectoring for stability control of the vehicle. Electrical power is stored in a lithium polymer battery pack optimised for energy density, efficiency and high-power demand, mounted in the centre of the vehicle for stability and safety.

Additional range is provided by the Lotus Range Extender engine, an optimised 1.2 litre, three-cylinder engine, designed specifically for series hybrid vehicles. The incorporation of Halosonic Internal and External Electronic Sound Synthesis technologies from Lotus and Harman International provide sound contouring within the cabin and improve pedestrian safety outside the vehicle. Integrated with the Halosonic technology, the Evora 414E Hybrid also features a sports mode that simulates a seven-speed, paddle-shift transmission that combines exceptional driver involvement for a hybrid sports car and optimised energy recuperation.

The Evora 414E Hybrid highlights Lotus's electric and hybrid vehicle technology without distracting from the pure sportscar character of the Evora. The Lotus Evora 414E Hybrid's drivetrain system consists of twin motors each limited to providing 152kW (207 PS/204 hp) of power and 400Nm (295lbft) of torque to each wheel via independent, single-speed, reduction transmissions integrated into a single housing, enabling torque-vectoring dynamic control of the vehicle. The vehicle energy-storage system is made up of the latest lithium-polymer battery chemistry, providing 17kWH energy-storage capacity.

The battery pack is optimised for energy density, efficiency and high power demand, with more than 100kW discharge capability. The Lotus Range Extender engine provides 35kW (48PS/47hp) of power at 3,500rpm via the integrated electrical generator and features an architecture comprising of an aluminium monoblock construction, integrating the cylinder block, cylinder head and exhaust manifold in one casting. This results in reduced engine mass, assembly costs, package size and improved emissions and engine durability. The engine uses an optimised two-valve, port-fuel injection combustion system to reduce cost and mass and can be operated on alcohol-based fuels and/or gasoline.

The generator converts mechanical energy to electrical energy to replenish the battery-pack charge and provides additional vehicle range in a small lightweight package. The generator is also used as a motor to start the range-extender engine. The low mass of the range-extender unit (85kg) and compact package make it ideal for the hybrid drivetrain in the Evora 414E Hybird. All the operation and management of the range-extender engine, the power management of the batteries and motor control are controlled by Lotus's electronic-control units and software systems. Full energy management of all the operating systems is the key to maximising performance and operation while minimising energy consumption and CO2 emissions.

For everyday commuting journeys, up to 35 miles can be travelled using battery power. The battery can be charged overnight using a conventional domestic mains supply through a socket concealed by the rear number plate. This allows the vehicle to operate with zero tailpipe emissions. For longer journeys exceeding the battery capacity, the efficient range-extender engine is used as a generator to supply the motor with electrical power and top up the battery. Lotus has used its own vehicle-simulation tools to determine the size, capacity, power and performance of all the components in the drivetrain system to optimise the system operation.

Overall this is far more energy efficient, weight efficient and cost effective than fitting the vehicle with a larger and more expensive battery, which for the majority of short journeys is a redundant weight, increasing energy requirements. With regard to the total lifetime CO2 emissions of the vehicle, including the energy required to manufacture and run it, the range extender solution has a lower overall CO2 footprint than a fully electric car of comparable performance and operating range running with a larger battery.