The Lotus Evora 414E Hybrid concept derives its name from its metric horsepower rating of 414 PS (408 SAE horsepower). Its plug-in series hybrid drive system is configured like the Chevy Volt's, but instead of using an off-the-shelf engine designed to provide the full range of functionality needed for "normal" car, it gets a dedicated 3-cylinder generates 47 hp at 3,500 rpm via the integrated electrical generator. The engine features an innovative aluminum monoblock integrating the block, head and exhaust manifold in one casting to reduce engine mass (it weighs just 187 pounds), assembly costs, package size. It's also said to improve emissions and engine durability. It's low-tech, using two valves per cylinder and port-fuel injection, but it runs on gasoline, ethanol, methanol, or combinations of any.
Acceleration to 60 mph is claimed to take less than 4 seconds. Electric-only range is quoted at 35 miles, with hybrid range at 307. An Eco mode helps optimize those numbers, but perhaps more important for Lotus is the Sports mode, which offers paddle shifters and a "HALOsonic" Internal and External Electronic Sound Synthesis system to simulate realistic 7-speed acceleration and deceleration. The system, designed in conjunction with harmon international, offers four driver selectable engine sounds--a V-6, a V-12, a futuristic sound (think Tron bike) and a combination of the futuristic one overlaid on the conventional engine. The faux engine note is played through two Harmon/Kardon GreenEdge external speakers (one at the front and one in back), and through the vehicle's sound system inside, and will eventually provide cancellation of the range-extender's engine noise. The V-6 and V-12 are realistic sounding, but play in a very bass register--nothing to suggest Italian power, it's more Yank six or Bentley 12 sound. Playing with the paddles under acceleration could actually slow the car down a bit (it has to taper torque slightly before each shift to give you the up-shift shove in the back), but it's quite useful for providing precise control of the regenerative braking during deceleration.
To optimize handling, power is delivered by two electric motors at the rear, driving each of the rear wheels independently via a single speed gear reduction integrated into a common transmission housing. This enables torque vectoring for stability control and enhanced turn-in. Each motor is limited to providing 204 hp of power 295 lb.-ft. of torque to its wheel. Lithium Polymer battery chemistry provides 17 kWH of energy storage capacity. The battery pack is optimized for energy density, efficiency and high power demand, with over 100 kW discharge capability.
Of all the electric and hybrid-electric sports cars on the Geneva show floor, this one and the Porsche 918 are the most promising. Stay tuned for imminent test drives as these two progress toward production.