The production Lotus Engineering / Fagor Ederlan Range Extender is an extremely compact, lightweight, low-cost engine and generator, designed specifically for hybrid electric vehicles. The initial concept engine is fitted to a number of research vehicles, including the Lotus Evora 414E, the Infiniti Emerg-e and the Jaguar Limo Green and this new version has been redesigned by Lotus Engineering and Fagor Ederlan to optimise performance and develop the engine for series production.
The production 3 cylinder Lotus Engineering / Fagor Ederlan Range Extender will be offered in two versions with the top of the range 50 kW supercharged variant on show in the cutaway hybrid Evora 414Evolution exhibit. The 1.3 litre, three cylinder Lotus Range Extender engine offers high efficiency and low mass, which will enable the downsizing of expensive batteries, whilst maintaining vehicle efficiency and range of hybrid electric vehicles.
The Range Extender is designed to offer a fast route to market for original equipment manufacturers requiring a dedicated range extender for series hybrid vehicles. Designing the engine specifically for hybrid applications has provided a number of opportunities to significantly reduce the mass of the engine. This mass optimisation has resulted in an engine weight of 58 kg for the supercharged version and 51 kg for the naturally aspirated variant.
The supercharged engine uses a belt driven centrifugal supercharger to produce 50 kW peak electrical power at 3500 rpm, with the naturally aspirated version producing a maximum 35 kW. The engine is optimised to generate power at engine speeds between 1500 and 3500 rpm allowing a lightweight simple 2 valve per cylinder engine architecture and eliminating the need for a complex 4 valve per cylinder design.
As well as an Integrated Exhaust Manifold, the Lotus Range Extender engine has an innovative new Integrated Intake Manifold that gives a significant reduction in weight and package size.
The generator supplied by Fagor Automation, is driven directly off the crankshaft to reduce weight, package size and cost. The engine, generator and power electronics are controlled using a Lotus controller to improve communication and efficient running of the systems. The engine architecture and engine management system are designed to offer flex-fuel capability to allow the engine to run on renewable alcohol fuels.