Lotus Engineering unveiled its Range Extender engine at the 63rd Frankfurt International Auto Show. In a production hybrid vehicle, the Range Extender engine will be attached to an electricity generator and provide a highly efficient source of energy to power the electric motor directly or charge the vehicle’s battery. The battery can also power the electric motor, which enables the design of a drivetrain that has low emissions, optimized performance and acceptable range.
The Lotus Range Extender engine features an innovative architecture with an aluminum monoblock construction, integrating the cylinder block, head and exhaust manifold into one casting. The result is reduced engine mass, assembly costs, package size as well as improved emissions and durability.
The three-cylinder 1.2 liter Range Extender engine is optimized between two power generation points, giving 15kW of electrical power at 1500rpm and 35kW at 3500rpm via the integrated electrical generator. Its low mass of 123 lb makes it ideal for the production hybrid drivetrain configurations it was designed for. The engine uses a two-valve port-fuel injection combustion system to reduce cost and mass and, in line with Lotus Engineering’s extensive research into renewable fuels, can be operated on alcohol-based fuels or gasoline.
For consumers to buy hybrid vehicles with acceptable driving range, vehicle manufacturers must overcome the challenges of high vehicle cost. The Lotus Range Extender engine not only offers the advantage of a cost effective design, but its high efficiency and low mass will enable the downsizing of expensive batteries while maintaining vehicle efficiency and range. The engine has been designed using production methods and the parts procured from low volume suppliers, offering a fast route to market for original equipment manufacturers wanting to source a dedicated range extender for its hybrid vehicles.