Overview: Jaguar C-X75

Jaguar’s C-X75 concept, which made its début at the Paris Salon, is an extended-range electric vehicle with two main headline features. First, it is exceptionally powerful: four 197PS electric motors are deployed, one driving each wheel and individually controlled, providing the car with a total of 788PS and an almost ludicrous 1600Nm, the latter figure available from the first revolution of the motors. Each motor weighs 50kg.

Secondly, the range-extender engine is (or are) a pair of small gas turbine units, engineered in collaboration with Shropshire-based Bladon Jets. Each turbine unit weighs a modest 35kg and produces 95PS. They run at a steady 80,000rpm. Quoted CO2 yield is 28g/km across the vehicle’s full range. The miniaturised turbine blade — described as the first viable axial-flow micro-turbine — increases the compression and efficiency of micro gas-turbines to the point at which they can be seen as a realistic power source.

Gas turbine engines will run on conventional LPG, or on bio-fuels with similar characteristics. In the Jaguar, they are combined with switched reluctance motors, which act initially as starters and then as generators. This type of motor is simple, lacking a commutator, and offers good reliability in service: the individual phase windings are electrically isolated from each other, so if one phase shorts, the others are not affected and the motor can continue to function. SRMs are commonly used to start the jet engines of aircraft and work as generators once the jet is running.

Given the C-X75’s vital statistics, along with a moderate kerb mass of 1350kg, it is not surprising that acceleration is laughably quick: 100km/h is reached from a standing start in 3.4s. The Jaguar’s maximum speed — with the turbines running to sustain the battery — is 205mph. On a more practical level, C-X75 will run for a quoted 110km before the range-extenders fire up; the car’s total range is 900km. It’s probably fair to say that a car like this will not be used principally for urban commuting, so the gas turbines will probably see more action than the range-extenders of other series hybrids.

The C-X75’s bodyshell follows the current XJ saloon in its construction, with an extruded and bonded aluminium chassis clad in panels of the same material.

Jaguar has deployed active aerodynamics to control airflow around and through the C-X75. The front grille and brake cooling vents are opened only when necessary; at the rear corners of the car, vertical control surfaces automatically engage at higher speeds to direct airflow aft of the rear wheels for increased stability and efficiency. The carbon-fibre rear diffuser, which guides airflow under the car and creates downforce at the rear, includes an active aerofoil which is lowered automatically as speed increases. Vanes in the exhaust ports then alter the direction of flow of the gases to increase the effectiveness of the venturi.

Inside

Aside from the usual whacky show car styling, the C-X7’s interior architecture is based on racing-car principles: the seats are fixed, while the steering wheel, controls, main binnacle and pedal box are adjustable.

A new interface for the driver has been created for the C-X75 using high-resolution TFT screens. The main driver information screen is housed within the instrument binnacle; needles float on the periphery of the twin cowls and sweep round the outer edge to display the status and shaft speeds of the two turbines. Virtual gauges wrap and rotate to provide status updates.

Jaguar
C-X75
Cylinders 2GT
Compression
ratio
N/S
Operating
rpm
80,000
PS 190
Nm N/S
Motors PS 788
Motors Nm 1600
Battery
— type
— capacity
— mass

Li-ion
19.6kWh
230
Generators Two switched reluctance
Maximum speed 205
0-100km/h 3.4
CO2 g/km 28
Transmission (1)
Driven wheels All
Fuel tank 60l
Electric range 68 miles
Total range 560 miles
Kerb mass 1350
PS/t 583
Nm/t 1185
Length 4647
Width 2020
Height 1204
Wheelbase 2725
Tyres
— front
— rear

265/30x21
356/25x22
Cd 0.32
(1) Single-speed reduction gear.
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