The engine Range Extender

Lotus Engineering, the world-renowned automotive consultancy division of Lotus, unveils its Range Extender engine at the 63^rd Frankfurt International Motor Show.  In a series hybrid vehicle, the Range Extender engine is attached to an electricity generator and provides a highly efficient source of energy to power the electric motor directly or charge the vehicles battery.  The battery can also power the electric motor which enables the design of a drive train that has low emissions, optimised performance and acceptable range.

The Lotus Range Extender engine features an innovative architecture comprising an aluminium mono block 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 three-cylinder 1.2 litre Range Extender engine is optimised between two power generation points, giving 15 kW of electrical power at 1,500 rpm and 35 kW at 3,500 rpm via the integrated electrical generator.  Its low mass of 56 kg makes it ideal for the series hybrid drive train configurations for which it is designed.  The engine uses an optimised 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 successful market uptake of series 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 also its high efficiency and low mass will enable the downsizing of expensive batteries whilst maintaining vehicle efficiency and range. The engine has been designed using production methodologies and the parts procured from low volume potential production suppliers, offering a fast route to market for original equipment manufacturers wanting to source a dedicated range extender for series hybrid vehicles.

Key features include zero emissions when in EV mode but Euro 6 compliant enjoying a fuel flexibility capability for the ICE (IE the use of bio fuels). The removal of the ‘Range Anxiety’ for EVs and the removal of dependency on charging points are significant added advantages.

Left is       RE50/RE35 capable of generating up to 55kW or 38kW at 3500 rpm

Right is    RE30/RE20 capable of generating up to 33kW or 23kW at 3500rpm respectively

To demonstrate their faith in the Range Extender, Lotus has installed the power plant into their new 414e Evora Sportscar.

All pictures courtesy of Lotus Engineering