Fisker Karma EV to offer ‘world-class’ dynamics

NICHE electric vehicle sportscar marque Fisker Automotive has vowed that its inaugural Karma four-door plug-in hybrid sedan, which is due for release in Europe in September, will offer “world-class ride and handling characteristics” and, to prove it, has released details of the vehicle’s aluminium space-frame chassis.

To be shown at the Geneva motor show on March 2, the Karma’s underpinnings are engineered around the so-called Q-Drive series-hybrid powertrain, which drives the rear wheels via two 150kW electric motors mounted on the rear differential, with extra performance derived from a GM-sourced 2.0-litre four-cylinder ‘Ecotec’ petrol engine that acts as a generator rather than a drive unit.

Described as the “world’s first luxury plug-in hybrid vehicle”, the Karma is claimed to be able to accelerate from 0-100km/h in “about six seconds” and will have a maximum speed of 201km/h when operating in hybrid ‘Sport’ mode. It will also have a 2.4L/100km combined fuel consumption rating and a total driving range of 483km.

In pure-electric ‘Stealth’ mode, Fisker claims the Karma will have an 80km range, a seven-second 0-100km/h time and a 153km/h top speed.

Full specifications are still to emerge for the Karma, which will be built in Finland by contract manufacturer Valmet Automotive, but the information released this week ahead of the Geneva show does add some important detail.

Fisker claims that the space frame – which is said to be all-new rather than adapted from another manufacturer – incorporates “new levels of rigidity and strength” that will guarantee world-class vehicle dynamics.

Left: Fisker Karma S.

It said “few cars match its statistics”, with static torsional rigidity measuring more than 33,000Nm per degree, static bending rigidity at more than 23,000N/mm, and dynamic stiffness “also world-class”.

“Our top priorities when we designed the Karma’s aluminium space frame were that it have extremely high torsional rigidity and could be easily modified to accept Karma model variants,” said Fisker Automotive CEO Henrik Fisker, referring to the four-door and the two-door Karma S convertible shown at the Detroit motor show last year.

“We benchmarked some of the world’s best cars to create an all-new space frame that will deliver an exhilarating experience behind the wheel.”

According to Fisker, a “super-structural” tunnel running down the car’s centreline acts as the Karma’s backbone, housing the lithium-ion battery pack and also acting as a torque tube connecting front and rear sections.

For optimal strength, the space frame is joined with 79 metres of precision welding and 1058 self-piercing rivets. Each technique is used independently only where necessary “to ensure top quality and durability”.

Fisker said the Karma’s space frame will also provide high levels of occupant safety and will exceed global crash protection standards.

Frontal protection includes a (patent-pending) multi-cell tempered aluminium crush box that can absorb an impact and is also designed to be easily replaced to reduce repair costs.

Side-impact protection includes dual-phase 600-series steel reinforced components in the doors and B-pillars. The battery’s location in the centre of the car is also well removed from common impact areas.

A former Aston Martin and BMW designer who founded Fisker Automotive in 2007 with partner Bernhard Koehler, Mr Fisker said recently that he was in the process of purchasing an idled General Motors plant in Wilmington, Delaware, from where he plans to export more than 50,000 EVs a year once up and running.

This represents a third of the plant’s planned production capacity.

Apart from the Karma S, there is another Karma-based model variant in the pipeline, along with a second line – understood to be a medium-sized family – due for release in 2012.